In the meantime, post the configuration you've used for testing to be bullet-proof, although I'm afraid I may not find anything. See my automatic signature for instruction.
Thank you for looking into it! Here is the config:
# jul/18/2018 22:27:15 by RouterOS 6.42.6
# software id = BVJ0-75V5
#
# model = RBD52G-5HacD2HnD
# serial number = XXXX
/interface bridge
add admin-mac=B8:69:F4:18:91:7B auto-mac=no comment=defconf name=bridge
/interface pppoe-client
add add-default-route=yes disabled=no interface=ether1 keepalive-timeout=\
disabled max-mtu=1492 name=pppoe-out1 password=XXXXX user=\
XXXXXXXX
/interface wireless
set [ find default-name=wlan1 ] band=2ghz-b/g/n channel-width=20/40mhz-Ce \
distance=indoors frequency=auto mode=ap-bridge ssid=MikroTik-18917F \
wireless-protocol=802.11
set [ find default-name=wlan2 ] band=5ghz-a/n/ac channel-width=\
20/40/80mhz-Ceee distance=indoors frequency=auto mode=ap-bridge ssid=\
MikroTik-189180 wireless-protocol=802.11
/interface list
add comment=defconf name=WAN
add comment=defconf name=LAN
/interface wireless security-profiles
set [ find default=yes ] supplicant-identity=MikroTik
/ip hotspot profile
set [ find default=yes ] html-directory=flash/hotspot
/ip pool
add name=default-dhcp ranges=192.168.88.201-192.168.88.250
/ip dhcp-server
add address-pool=default-dhcp disabled=no interface=bridge name=defconf
/ppp profile
add local-address=192.168.88.251 name=SSTP01-adn remote-address=\
192.168.88.252 use-encryption=required
/interface bridge port
add bridge=bridge comment=defconf interface=ether3
add bridge=bridge comment=defconf interface=ether4
add bridge=bridge comment=defconf interface=ether5
add bridge=bridge comment=defconf interface=wlan1
add bridge=bridge comment=defconf interface=wlan2
/ip neighbor discovery-settings
set discover-interface-list=LAN
/interface list member
add comment=defconf interface=bridge list=LAN
add comment=defconf interface=ether1 list=WAN
add interface=ether2 list=WAN
add interface=pppoe-out1 list=WAN
/interface sstp-server server
set certificate=server default-profile=SSTP01-adn enabled=yes force-aes=yes \
pfs=yes
/ip address
add address=192.168.88.1/24 comment=defconf interface=bridge network=\
192.168.88.0
/ip cloud
set ddns-enabled=yes update-time=no
/ip dhcp-client
add comment=defconf dhcp-options=hostname,clientid interface=ether1
add default-route-distance=2 dhcp-options=hostname,clientid disabled=no \
interface=ether2
/ip dhcp-server lease
add address=192.168.88.99 mac-address=XXXXXXXXXXXX
add address=192.168.88.9 mac-address=XXXXXXXXXXXX
add address=192.168.88.8 mac-address=XXXXXXXXXXXX
add address=192.168.88.7 mac-address=XXXXXXXXXXXX
add address=192.168.88.4 mac-address=XXXXXXXXXXXX
add address=192.168.88.10 mac-address=XXXXXXXXXXXX
add address=192.168.88.6 mac-address=XXXXXXXXXXXX
add address=192.168.88.5 mac-address=XXXXXXXXXXXX
/ip dhcp-server network
add address=192.168.88.0/24 comment=defconf gateway=192.168.88.1
/ip dns
set allow-remote-requests=yes servers=8.8.8.8
/ip dns static
add address=192.168.88.1 name=router.lan
/ip firewall filter
add action=accept chain=input comment=\
"defconf: accept established,related,untracked" connection-state=\
established,related,untracked
add action=drop chain=input comment="defconf: drop invalid" connection-state=\
invalid
add action=accept chain=input comment="defconf: accept ICMP" protocol=icmp
add action=drop chain=input comment="defconf: drop all not coming from LAN" \
in-interface-list=!LAN
add action=accept chain=forward comment="defconf: accept in ipsec policy" \
ipsec-policy=in,ipsec
add action=accept chain=forward comment="defconf: accept out ipsec policy" \
ipsec-policy=out,ipsec
add action=fasttrack-connection chain=forward comment="defconf: fasttrack" \
connection-state=established,related
add action=accept chain=forward comment=\
"defconf: accept established,related, untracked" connection-state=\
established,related,untracked
add action=drop chain=forward comment="defconf: drop invalid" \
connection-state=invalid
add action=drop chain=forward comment=\
"defconf: drop all from WAN not DSTNATed" connection-nat-state=!dstnat \
connection-state=new in-interface-list=WAN
/ip firewall nat
add action=masquerade chain=srcnat comment="defconf: masquerade" \
ipsec-policy=out,none out-interface-list=WAN
add action=dst-nat chain=dstnat dst-port=38623 in-interface-list=WAN \
protocol=tcp to-addresses=XXXXXXXXXXXX to-ports=XXXXX
add action=dst-nat chain=dstnat disabled=yes dst-port=XXXXX in-interface=\
bridge protocol=tcp to-addresses=XXXXXXXXXXXX to-ports=XXXXX
add action=dst-nat chain=dstnat dst-port=XXXXX in-interface-list=WAN \
protocol=udp to-addresses=XXXXXXXXXXXX to-ports=XXXXX
add action=dst-nat chain=dstnat dst-port=9623 in-interface-list=all protocol=\
tcp to-addresses=XXXXXXXXXXXX to-ports=XXXXX
/ppp secret
add name=sstp-adn01 password=test profile=SSTP01-adn service=sstp
/system clock
set time-zone-name=Europe/Bucharest
/system ntp client
set enabled=yes primary-ntp=XXXXXXXXXXXX secondary-ntp=XXXXXXXXXXXX
/system routerboard settings
set silent-boot=no
/system scheduler
add disabled=yes interval=10m name=schedule1 on-event="#----------------------\
-----------------------------SCRIPT INFORMATION---------------------------\
-------------------------\
\n#\
\n# Script: Marthur's No-IP.com Dynamic DNS Update Script\
\n# Version: 1.0\
\n# Updated: 10/21/2017\
\n# Created: 10/21/2017\
\n# Author: Marthur Jones\
\n# Website:
https://www.marthur.com\
\n#\
\n# This script is to be used in conjunction with No-IP.com's Dynamic DNS \
Service. It is to be scheduled/ran on a Mikrotik \
\n# router as replacement for No-IP's Dynamic Update Client for Windows. T\
here are many versions of this script. However, \
\n# I've made my own modifications to the original script that was created\
\_on March 13, 2012 by riverron and published on\
\n# the MikroTik Wiki here:\
\n#\
\n#
https://wiki.mikrotik.com/wiki/Dynamic_ ... _No-IP_DNS\
\n#\
\n# - Changed the scope of the variable that stores the previous IP addres\
s from global to local. The local variable's value \
\n# (IP address) is now assigned via MikroTik's DNS resolution. The scri\
pt compares the previous IP with the current IP \
\n# that is assigned to the WAN interface, if the IP addresses do not ma\
tch, the script will update the No-IP hostname\
\n# with the IP assigned to the WAN interface.\
\n#\
\n# - Added variable to define the log destination path that the script pu\
lls from No-IP.com after a DDNS IP update.\
\n#\
\n# - Made variable name changes.\
\n#\
\n#-----------------------------------------------TESTED USING THE FOLLOWI\
NG------------------------------------------------\
\n#\
\n# Hardware: CCR1009-7G-1C-1S+\
\n# Firmware: v3.41\
\n# RouterOS: v6.40.4\
\n#\
\n#----------------------------------------------MODIFY THIS SECTION AS NE\
EDED----------------------------------------------\
\n\
\n# No-IP account credentials.\
\n:local noipUsername \"XXXXXXXXXXXX"\
\n:local noipPassword \"XXXXXXXXXXXX"\
\n\
\n# Set the hostname or label of network to be updated.\
\n# Hostnames with spaces are unsupported. Replace the value in the quotat\
ions below with your host names.\
\n# To specify multiple hosts, separate them with commas.\
\n:local noipHostname \"XXXXXXXXXXXX"\
\n\
\n# The interface name with the assigned dynamic IP address (usually the W\
AN interface).\
\n:local wanInterface \"pppoe-out1\"\
\n\
\n# Log destination\
\n:local logDestination \"/disk1/logs/\"\
\n\
\n#-----------------------------------------------------------------------\
--------------------------------------------------\
\n\
\n:log warning message=\"START: No-IP DDNS Update\"\
\n\
\n:if ([/interface get wanInterface value-name=running] = true) do={\
\n\
\n# Get the previous IP via DNS resolution.\
\n :local previousIP [:resolve \"\$noipHostname\"]\
\n\
\n# Get the current IP on the WAN interface.\
\n :local currentIP [/ip address get [find interface=\"\$wanInterface\"\
\_disabled=no] address]\
\n\
\n# Strip net mask from IP address.\
\n :for i from=([:len \$currentIP] - 1) to=0 do={\
\n :if ([:pick \$currentIP \$i] = \"/\") do={\
\n :set currentIP [:pick \$currentIP 0 \$i]\
\n }\
\n }\
\n\
\n :log info \"No-IP: DNS IP (\$previousIP), interface IP (\$currentIP)\
\"\
\n \
\n :if (\$currentIP != \$previousIP) do={\
\n :log info \"No-IP: Current IP \$currentIP is not equal to previo\
us IP, update needed\"\
\n\
\n# The update URL. The \"\\3F\" is hex for question mark (\?). This\
\_is required since \? is a special character in the command.\
\n :local url \"
http://dynupdate.no-ip.com/nic/update\\3Fmyip=\$cur\
rentIP\"\
\n :local noipHostnames\
\n :set noipHostnames [:toarray \$noipHostname]\
\n :foreach hostname in=\$noipHostnames do={\
\n :log info \"No-IP: Sending update for \$hostname\"\
\n /tool fetch url=(\$url . \"&hostname=\$hostname\") user=\$no\
ipUsername password=\$noipPassword mode=http dst-path=(\$logDestination . \
\"no-ip_ddns_update-\" . \$hostname . \".txt\")\
\n :log info \"No-IP: Host \$hostname updated on No-IP with IP \
\$currentIP\"\
\n }\
\n } else={\
\n :log info \"No-IP: Previous IP \$previousIP is equal to current \
IP, no update needed\"\
\n }\
\n\
\n} else={\
\n :log info \"No-IP: \$wanInterface is not currently running, unable t\
o verify and/or update IP.\"\
\n }\
\n \
\n:log warning message=\"END: No-IP DDNS Update\"" policy=read,write,test \
start-date=jul/12/2018 start-time=20:07:49
add disabled=yes interval=1h name=schedule2 on-event="##############Script Set\
tings##################\
\n\
\n:local NOIPUser \"XXXXXXXXXXXX"\
\n:local NOIPPass \"XXXXXXXXXXXX"\
\n:local WANInter \"XXXXXXXXXXXX"\
\n\
\n###############################################\
\n\
\n:local NOIPDomain \"XXXXXXXXXXXX"\
\n:local IpCurrent [/ip address get [find interface=\$WANInter] address];\
\n:for i from=( [:len \$IpCurrent] - 1) to=0 do={ \
\n :if ( [:pick \$IpCurrent \$i] = \"/\") do={ \
\n :local NewIP [:pick \$IpCurrent 0 \$i];\
\n :if ([:resolve \$NOIPDomain] != \$NewIP) do={\
\n /tool fetch mode=http user=\$NOIPUser password=\$NOIPPass url=\"ht\
tp://dynupdate.no-ip.com/nic/update\\3Fhostname=\$NOIPDomain&myip=\$NewIP\
\" keep-result=no\
\n :log info \"NO-IP Update: \$NOIPDomain - \$NewIP\"\
\n }\
\n } \
\n}" policy=read,write,test start-time=startup
-MISSING LINES, SAME SCRIPTS-
/tool mac-server
set allowed-interface-list=LAN
/tool mac-server mac-winbox
set allowed-interface-list=LAN
