Hi,
There a few thing that could be happening.
Since you have SSH access, we can solve the issue
You could have blocked access to WebUI on the IP address
execute command: ubus call ip_block clear
Try to if you have regained access, if not then try to execute:
uci show firewall | grep HTTPS
you should get an ouput
firewall.17.name='Enable_HTTPS_WAN'
the 17 might be different
uci set fire firewall.<the number in my case it was 17>.enabled=1
uci set uhttpd.main._httpsWanAccess=1
uci commit
/etc/init.d/firewall reload
/etc/init.d/uhttpd reload