iPhone 8 Other takes up 50+GB

OK.....when you say you wiped the phone clean, did you do what is detailed in this link (make sure your data backed up) --> What to do before you sell, give away, or trade in your iPhone, iPad, or iPod touch - Apple Support

If this is what you did, there really is no way there could be 50GB of other remaining on the phone. It would be in the condition of a new phone, which opens to the Hello Page and would be ready to be set up.

Then set up the phone from the backup you have.

Try restoring the phone and do NOT restore from backup. It appears there is something in your backup which is corrupt. In a case like this, you would need to set the phone up manually and NOT from backup IF the restore gave you your memory back.

You are saying you factory reset your phone, meaning you wiped all data off the phone and yet "other" remained unchanged? Or did you mean you Force Restarted your phone?

That doesn't make sense.

I'd use the Get Support button at the top of this page or schedule an appointment at your Apple Store Genius Bar for help.

It might be your OS, but I don’t know. I’m so sorry. Hopefully you can fix the problem

Good.