If you manually change the config files, you apply the changes with service blahblah restart (reload might work too).
If you change via uci, you need to commit and then restart service.
If you change in Luci you can use the Save/Apply button.
I am running the latest master from yesterday.
Still the same problem.
If I change the setting in network config of a peer and after that I press Save&Apply nothing happens
The changes will not get applied till I do a /etc/init.d/network restart
Additional if I delete the wireguard network config the peers are not removed as well.
So If I add a new wireguard network config section the old peers are present again, because they were not delete before.