Well, I'm not sure about that app....but the dev even stated use at your own risk. However, you could see if they have a website or anything for help.
That said. Have you tried Odin to return to stock....and see if you still have issues???
If you want to try it, here's a guide. Links in OP are dead, but post 5 has some mirrors. Failing that, go to last page and read back to see if there are other links.
Good luck!! 👍
---------- Post added at 09:59 PM ---------- Previous post was at 09:59 PM ----------
Oh....an obvious question.... Did you try a new SIM?