Trying to connect via iPhone with Plus account. Error is that the phone isn’t connected to the Internet - yet it is, even posting to this sub using the connection.
UPDATE: The issue was the Proton app was not authorized for Cell Data. Once that was changed, all is good.
It’d help if the app notified the user that cell data was not authorized and needed to be on . . . 
I’m having issues connecting too. Checked cell data and that was already on. Every time it tries to connect it kicks me off my WiFi and never connects the VPN. Also not connecting over cell connection. Seems like there is an issue with today’s app update.
Update: phone restart fixed it.
Also had problems connecting, then I was logged out of my account. After restarting the phone the problem persisted and the WiFi symbol did not appear in the top right corner next to the battery symbol. Also could not update my inbox in the Proton Mail app as it said I was offline.
The only solution for me was to uninstall the VPN app.
For iPhone users go into Cellular Data settings and authorize the app for Cell Data. For android … 