Mike is having issues with his Macbook Air forgetting his passwords when he's online. He constantly has to log in. Leo says that this is a common problem with macOS, especially when you have 2 Factor Authentication enabled. And if you're using a VPN, your location isn't the same, which could be prompting macOS to make you log in again. Apple is good on security, obsessed with it actually. As such, it's likely that since Mike is using a VPN, the location changes, and thus, macOS requires a new login. So try turning off your VPN and see if the issue continues. Also, log into iCloud.com and see if everything is OK.
Rebooting can fix it, as well.