It is a fairly common sight on a "Nokia 7.1". Did you try this tutorial already? The slots can essentially take you 1 version behind and you can then try booting. Sometimes that works (as in the comments sent by many). And since you want to preserve your data, there's even lesser chance that it will work, but it can.
If not, what you can try is to go one ...
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 ...
OrangeFox Recovery allows option to lock Recovery with a Pattern or PIN
It will prevent normal youtube users from reseting your phone
but their is a catch people with deep knowledge will flash
Fastboot ROM or Qfil ROM and make device useable again but all data will be lost .
Best option is to use Phones in which bootloader unlock is not possible because ...