Watchdog constantly reboots PineTime when bluetooth connected in version 1.15.0

Verification

• I searched for similar bug reports (including closed issues) and found none was relevant.

What happened?

PineTime reboots immediately after connecting to a bluetooth device.

What should happen instead?

PineTime connects successfully to the bluetooth device and stays on after that.

Reproduction steps

Install pinetime-mcuboot-app-dfu-1.15.0.zip on PineTime with the previous memory chip (XTX XT25F32B, ref. https://github.com/InfiniTimeOrg/InfiniTime/issues/2096). For companion app I tried GadgetBridge (Android) and Amazfish (SailfishOS) with the same results. Keep the bluetooth active on the companion device, or activate it after PineTime boots with firmware 1.15.0, so the watch connects to the device.

If you want to experience several reboots without reverting to the previous firmware, you have to switch off bluetooth on the companion device right after the flashing is completed and before the PineTime completes booting, and you have to validate the firmware in the PineTime settings before switching on the bluetooth in the companion device. Otherwise, PineTime will try connecting during the first boot which will lead to rebooting and reverting to the previous firmware.

More details?

If bluetooth is disabled or not connected, the watch works as expected with all of its other functions.

If you don't validate the new firmware in the PineTime settings, reverting to the previous firmware after the first reboot leads to a fully working PineTime with the previous firmware.
But if you validate the new firmware, you have two options for reverting:

1. Reboot PineTime while keeping the button pressed until the pine logo turns blue. After that, PineTime will revert to the previous firmware;
2. (if the first doesn't help) Reboot PineTime while keeping the button pressed until the pine logo turns red. After that, PineTime will load some emergency firmware, which allows connecting to the companion device and you can flash some working firmware.

ATTENTION! No matter which of these two methods was used for reverting, it's not enough to clear the bluetooth problem. You have to boot PineTime with bluetooth disconnected (otherwise, PineTime will reboot again and switch to the validated new firmware), then validate the working firmware in the PineTime settings, manually reboot PineTime again (keep the button pressed while the pine logo is still white or green), and then you can switch on the bluetooth and connect to the companion device.

All the above is the same, no matter if the previous firmware is 1.14.0 or 1.14.1, or the bootloader is 1.0.0 or 1.0.1, or if you keep the added device in the companion app, or delete it after the flashing and make a new pairing after booting with 1.15.0. Clearing saved data, reinstalling and trying different versions of GadgetBridge and Amazfish doesn't help too.

It was fun to discover that PineTime keeps three firmware installations even after validating in the settings:

1. The main firmware which it boots by default;
2. The previous firmware that it reverts to, be it after rebooting non-validated firmware, or by going to the blue pine logo during the boot;
3. The strange emergency firmware, which can be loaded by going to the red pine logo during the boot. It doesn't tell what it is (just the text InfiniTime with its logo), you can do nothing on the watch (even to turn off the display, you can just reboot), but allows you to connect to the companion device and even vibrates when new message arrives.

Version

v.1.15.0, now back to 1.14

Companion app

Different versions of GadgetBridge and Amazfish

No source file or test is named. First reproduce the failure on PineTime with firmware 1.15.0, the previous XTX XT25F32 memory chip, and GadgetBridge or Amazfish while Bluetooth connects. Done means the watch connects successfully and remains running instead of entering the watchdog reboot and rollback cycle.