Fenix 6 Pro Dual Power (Asia market Solar) not connecting to any phone

So i bought a used Fenix 6 pro Dual power in japan, everything works perfectly, i can pair it to garmin express and everything, bluetooth pairing works (i can connect my phone to it using NRF Connect and pair my headphones directly to it). but no matter what i try, i cant connect it to the app on my S24 ultra nor my Iphone 14 pro. ive tried master reset, updating via garmin express on pc, restarting phone, reinstalling app, installing older version of app, everything i can think of. only thing i havent yet tried is to flash completely new software onto it, but im a bit hesitant on doing it.