Seems to be a trend with the 2020 SE when attempting to download the 14.0 beta. Got stuck on a white loading screen with a black Apple logo and loading bar that seemed to be stuck at 99% for 16 hours. Found something to force shutdown, quickly press volume up, quickly press volume down, press and hold the right Siri button. I did this while it was plugged into a computer as well, not sure if that has anything to do with it. The phone reset, completed the update, and (luckily) all my data was still there. I left the phone plugged into the computer while it completed the reset/update. Hope this helps someone.