Deeper Reset than Factory?
Virgin mobile is a proprietary prepaid Samsung Touchwiz Android repack - So that portion of the rom is not configurable.

What I would do is reflash the phone to North American Unlocked S7.

here's an XDA link with instructions.
it might be a bit of a pain but it will solve your problem utterly, and debloat your phone as well... making it a better phone quite frankly...

https://forum.xda-developers.com/galaxy-s7/help/sm-g930p-to-sm-g930u-t3813580