Have you tried connecting PC directly to MT to see what speedtest gives then ?
Without crystal ball ? No ...
pity i don't have crystal ball
at the moment i dont have USB to LAN, to try directly from MAC, so i've tried from Windows PC:
WiFi 2,4GHz: Down 28, up 13
LAN: Down: 55, up 4
# jul/29/2022 15:17:13 by RouterOS 6.49.2
# software id = 26W0-YUBZ
#
# model = RBwAPGR-5HacD2HnD
# serial number = xxx
/interface bridge
add admin-mac=xx:xx:xx:xx auto-mac=no comment=defconf name=bridge
/interface lte
set [ find ] allow-roaming=no name=lte1
/interface wireless
set [ find default-name=wlan1 ] band=2ghz-g/n channel-width=20/40mhz-XX \
country=lithuania disabled=no distance=indoors frequency=auto \
installation=indoor mode=ap-bridge ssid=. wireless-protocol=802.11 \
wps-mode=disabled
set [ find default-name=wlan2 ] band=5ghz-a/n/ac channel-width=\
20/40/80mhz-XXXX country=lithuania disabled=no distance=indoors \
frequency=auto installation=indoor mode=ap-bridge ssid=.. \
wireless-protocol=802.11 wps-mode=disabled
/interface list
add comment=defconf name=WAN
add comment=defconf name=LAN
/interface lte apn
set [ find default=yes ] name=internet.tele2.lv
/interface wireless security-profiles
set [ find default=yes ] authentication-types=wpa-psk,wpa2-psk mode=\
dynamic-keys supplicant-identity=MikroTik
/ip pool
add name=dhcp ranges=192.168.xx.150-192.168.xx.254
/ip dhcp-server
add address-pool=dhcp disabled=no interface=bridge lease-time=20h10m name=\
defconf
/interface bridge port
add bridge=bridge comment=defconf disabled=yes interface=ether1
add bridge=bridge comment=defconf interface=ether2
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=lte1 list=WAN
/ip address
add address=192.168.xx.1/24 comment=defconf interface=bridge network=\
192.168.xx.0
/ip dhcp-client
add disabled=no interface=ether1
/ip dhcp-server lease
add address=192.168.xx.199 client-id=1:e4:5f:1:a3:6e:a mac-address=\
xx:xx:xx:xx server=defconf
add address=192.168.xx.188 client-id=1:e4:5f:1:a3:6e:2 mac-address=\
xx:xx:xx:xx server=defconf
/ip dhcp-server network
add address=192.168.xx.0/24 comment=defconf gateway=192.168.xx.1
/ip dns
set allow-remote-requests=yes
/ip dns static
add address=192.168.xx.1 comment=defconf 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=accept chain=input comment=\
"defconf: accept to local loopback (for CAPsMAN)" dst-address=127.0.0.1
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
/ip service
set telnet disabled=yes
set ftp disabled=yes
set www disabled=yes port=20202
set www-ssl certificate=192.168.xx.1 disabled=no port=21212 tls-version=\
only-1.2
set api disabled=yes
set winbox disabled=yes
set api-ssl disabled=yes
/system clock
set time-zone-name=Europe/Riga
/system identity
set name=MikroTikLTE
/system package update
set channel=long-term
/tool mac-server
set allowed-interface-list=LAN
/tool mac-server mac-winbox
set allowed-interface-list=LAN
/tool sms
set port=lte1 receive-enabled=yes