same issue here!! upgraded my software 3 days ago to the new iOS 14 then 14.1 updates.
since then my phone signal has dropped off several times and I have to turn the phone off and back on again to have it reconnect. Also my new emails have issues loading and the email app freezes. Also battery drains a lot faster than before not to mention issues with Face ID being temperamental!
best part of all, I can’t go back to iOS 13 and am now stuck with these issues!!!! Bought iPhone 8 for my daughter to be able toy contact in case of emergencies and now has a phone that won’t connect!! What the hell Apple?! Been a loyal customer since first iPad release and all our devices in our home are Apple.... but this is really starting to test me!!!!!!!!