Guys, i have a specific issue. A week ago i bought a second hand pixel 9a preloaded with fresh install of grapheneos. Phone was used for a month or two. Battery health is 100% and 29 charging cycles. The phone is nice but after few days i wanted to try to revert it to stock google firmware. Did everything, removed grapheneos keys and unlocked bootloader through the fastboot, successfully flashed latest android 16 pixel 9a firmware with pixel flashing tool. On the welcome screen everything was alright until i got internet connection either through the sim card or wifi. As soon as the phone connected it showed factory resetting screen and it shutdown going straight to erasing circle. The thing is, it doesn't just factory reset it deletes the whole system and goes into fastboot with the message boot failed and locked bootloader. Anyways this only happens on official google software. I managed to unlock bootloader over adb and flash grapheneos and the phone is working fine but I've been flashing roms for over 10 years and never got an issue like this. The phone simply refuses official software. My guess is that either something is faulty hardware wise (but then it is weird how graphene is working normally), or the phone is somehow blacklisted by google and kills itself as soon as it has connection to google servers... Please do you have any ideas how to fix it or if it's fixable at all...