I've recently decided to switch over to Mint Mobile from my previous provider, Straight Talk.
However, I've run into a problem when trying to activate the SIM Card, it pops up as "SIM not supported".
I have an iPhone 8 plus, Model A1897, and was able to use Straight Talk services for 14 months with no problem. Not sure this will help, but prior to me using the phone, I acquired it 3rd party from someone who was an AT&T customer.
Has anyone had this kind of problem before? And, more importantly, how can we fix it?