I am seeing the same issue. I have multiple WebDAV vaults that have worked successfully for 2+ years. I am a premium user and can connect to them from my Windows 10 machine using Enpass 6.8.2 (1084), on my iPhoneX using Enpass 6.8.1 (633), but on my new MacBook (Apple M1 Pro) running macOS Monterey 12.3 I cannot add them all. The MacBook is running Enpass 6.8.2 (1082) from the Mac App Store. On the Mac I was able to get a second WebDav vault to work, but could not add anymore after I added the second one. Note a week prior it would not let me add the second folder with the same error I am getting now "No two vaults can be connected to same account for syncing data. Connected Vault: Family All"