Yap, the closing my VPN did it for several weeks ago.
I had the same problem with my Trustwallet app then, the support unit suggested i turned off my VPN and it worked instantly!
It has nothing to do with VPN you can even run Electrum without connecting it on wifi or data.
The only solution that I see is to reset it to factory default as Dabs suggested above or wipe the whole data and cache since he mentions "it was working before" so wiping the phone will bring it back to original settings and clear data and cache. The only problem with this it will delete all data from your phone and not recommended if you don't know the email connected to your phone because it might end up FRP.