Help - AVAST wont stop alerting me

I have recently changed the sim in my phone and Avast alerted me to it. I logged in and marked the phone as ‘found’ and safe, but everytime I turn it off and on, it goes back to the way it was and alerts me again. I’ve even deleted it from Avast and re-added it and it still happens. Does anyone know if I’m doing anything wrong or if it’s some kind of glitch? Would be a shame to not have Avast anymore.

https://forum.avast.com/index.php?board=38.0