I have a Note 10+ Sprint T-Mobile that will not factory reset. I have tried it three times now. It reboots as if I never tried.
I have an S10+ that keeps giving me pop-ups that read Samsung Account keeps stopping, then gives you 2 options that neither work, Force stop and App info. I've contacted Samsung and after a few hours on chat with them it's still doing the same thing. Ugghhh
Have you tried factory reset from recovery mode? To get to recovery mode turn the phone off. Once it is fully of then press and hold the power and volume up buttons. When you see the phone turn on you can release them and you should be hearing to recovery mode. Once there you use the volume buttons to navigate the menu and the power to select the action. Also note a factory reset will erase all data on your phone so be sure you have everything you want backed up.