I want to know the same thing. So dumb that its sold as an unlocked phone but still wont work with other carriers.
My V50 sprint unlocked was working with mint mobile after editing the APN but ever since I updated to Android 10 it no longer allows me to ad an APN, Delete one, or edit.
I thought this thread was going to be really helpful but after trying everything my APN settings are still grayed out. Sprint, LG, TMobile, and Mint mobile (my provider) all dont have any idea what to do about it.
I have already tied "##3282#" and got my correct "Service Code" from the Ebay seller to attempt the what l1lpiggy says to do in that thread, but that didn't change anything, APN settings are still greyed out.