This had me pulling my hair from my head for a couple of days.
Setting up a wireguard VPN with RouterOS and macos client is not that hard. Until you run into the web interface bug I ran into.
Configuring the interface and/or the peer via the web interface does not work, at least for me. Peer is configured correctly and even the console shows the configuration. But the handshake never happens. The counters remain zero. The client complains that the handshake times out. In the firewall I can see the initial packet coming in and is accepted. I tried all permutations of configuration. I blamed macos, I blamed iOS etc.
Then I configured an interface and peer via the console, and magic happened. It worked first time as all the articles/forum posts promised it would.
So this post is mainly to inform other users that are battling. I will be filing a bug report.
Summary: Don't use the web interface to configure interface and peer, use the console. I really hope someone finds this useful.