GSI-GMS image bootloop, non-GMS works fine

Flashing the ARM64 version (Android 11 or 12) from [here](https://developer.android.com/topic/generic-system-image/releases) works fine on my Blackview BL6000 Pro. However, flashing any ARM64+GMS only boots into the bootloader (not fastbootd). In general, how would one investigate why this happens? I can boot into the Stock Recovery, however, I cannot adb into the device because it shows up as unauthorized (perfectly authorized in the OS though). Unfortunately, afaik there's also no custom recovery available for my device. I thought about reading logcat or dmesg but I don't see a way to access them without having adb access. Thanks for any hints. Here's my procedure: 1. SP Flash the stock rom 2. Unlock the bootloader in the dev options 3. adb reboot bootloader 4. fastboot flashing unlock 5. fastboot reboot fastboot 6. fastboot delete-logical-partition product(this is necessary because the GSI is larger than the stock rom system partition) 7. fastboot erase system 8. fastboot flash system aosp-system.img (automatically resizes system) 9. fastboot -w 10. fastboot reboot which lands me in the OS for the non-GMS version, and in the bootloader for the GMS version.