Ah, well that complicates things.
It might just be an issue with the beta that broke your updates.
I know of a way to fix it, but it's not going to be pretty.
A solid fix should be using smart switch on a pc. Putting the phone into download mode and using the emergency software recovery option in smart switch. It will wipe everything from your phone but it should install the latest version of android with the latest update. That should fix things. It's just a little complex and involves wiping your data.
Try other things before this. But that should be a solid fix. Hopefully
