I think I have the issue figured out.
It seems Admin access will not be enabled on a port unless the port is assigned to a Bridge under Bridge>Bridge AND also assigned to an interface list under Interfaces>Interface List. This seems to apply both to IP Address connections & MAC Address connections to the router (in WinBox).
In my earlier attempts, I had to move the WAN port into the LAN Bridge in order to enable WebFig & Winbox admin over ether1 (WAN) port. This worked since it gave ether1 an entry on the Bridge page.
Current Configuration:
# mar/06/2023 23:13:10 by RouterOS 6.49.7
# software id = EZH7-EEL2
#
# model = RBD52G-5HacD2HnD
/interface bridge
add comment="Remove later" name=Bridge_WAN
add admin-mac=18:FD:74:DD:09:6B auto-mac=no comment=defconf name=bridge
add comment="Management port" name=bridge2
/interface wireless
set [ find default-name=wlan1 ] band=2ghz-b/g/n channel-width=20/40mhz-XX \
distance=indoors frequency=auto installation=indoor mode=ap-bridge ssid=\
MikroTik-DD096F wireless-protocol=802.11
set [ find default-name=wlan2 ] band=5ghz-a/n/ac channel-width=\
20/40/80mhz-XXXX distance=indoors frequency=auto installation=indoor \
mode=ap-bridge ssid=MikroTik-DD0970 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=hotspot
/ip pool
add name=default-dhcp ranges=192.168.88.10-192.168.88.254
add name=dhcp_pool1 ranges=192.168.80.2-192.168.80.254
add name=dhcp_pool2 ranges=192.168.70.2-192.168.70.254
/ip dhcp-server
add address-pool=default-dhcp disabled=no interface=bridge name=defconf
add address-pool=dhcp_pool1 disabled=no interface=bridge2 name=dhcp1
add address-pool=dhcp_pool2 disabled=no interface=Bridge_WAN name=dhcp2
/interface bridge port
add bridge=bridge comment=defconf interface=ether2
add bridge=bridge comment=defconf interface=ether3
add bridge=bridge comment=defconf interface=ether4
add bridge=bridge2 comment=defconf interface=ether5
add bridge=bridge comment=defconf disabled=yes interface=wlan1
add bridge=bridge comment=defconf disabled=yes interface=wlan2
add bridge=Bridge_WAN comment="Remove later" interface=ether1
/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=bridge2 list=LAN
/ip address
add address=192.168.88.1/24 comment=defconf disabled=yes interface=bridge \
network=192.168.88.0
add address=192.168.80.1/24 interface=bridge2 network=192.168.80.0
add address=192.168.70.1/24 interface=Bridge_WAN network=192.168.70.0
/ip dhcp-client
# DHCP client can not run on slave interface!
add comment=defconf disabled=no interface=ether1
/ip dhcp-server network
add address=192.168.70.0/24 dns-server=8.8.8.8 gateway=192.168.70.1
add address=192.168.80.0/24 dns-server=8.8.8.8 gateway=192.168.80.1
add address=192.168.88.0/24 comment=defconf dns-server=192.168.88.1 gateway=\
192.168.88.1
/ip dns
set allow-remote-requests=yes
/ip dns static
add address=192.168.88.1 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=accept chain=input comment="WinBox Wan Administration" dst-port=\
8291 protocol=tcp
add action=accept chain=input comment="HTTP WAN Admin" dst-port=80 protocol=\
tcp
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
/tool mac-server
set allowed-interface-list=LAN
/tool mac-server mac-winbox
set allowed-interface-list=LAN