As of today, Enpass 6.11.4 (1800) on my Mac Mini M2 Pro shows this error under Vault Settings:

Sync Error
Password of data on Wi-Fi Sync Server is required

But Enpass on this Mac is the Wi-Fi Sync Server for all other devices and it has the status Running when I check in Settings>>Wi-Fi Sync.

I don't understand how I can resolve this issue without disconnecting all sync clients and connecting them again.
There's the option 'Resolve Now', but there my Master Password is not accepted.

So why does the Wi-Fi Sync Server require its own Wi-Fi Sync Server password and which one would that be?

 

If you prefer not to disconnect all sync clients, the best approach is to initiate the Wi-Fi sync setup directly from the affected device. This should allow you to reconnect the server without having to remove it from all devices.

Ok, then, setting up Wi-Fi Sync again on all of my devices.