Hi,
I have just configured wireguard on mikrotik based on following guide on http://forum.mikrotik.com/t/mikrotik-wireguard-server-with-road-warrior-clients/148392/1
It is working fine but when I try to connect to winbox after connecting to vpn , it is not possible.
In firewall I have created an admin list with ip that are allowed to connect to mikrotik. Also added firewall filter rule to allow connection to port 8291 for those specific ip addresses.This rule works fine for ikev2 vpn but not for wireguard.
You might want to consider adding wireguard to the LAN interface-list. That is by far the fastest solution. But that is something you might need to consider.