CircuitPython version

Adafruit CircuitPython 7.0.0-rc.1 on 2021-09-02; Adafruit FunHouse with ESP32S2

Code/REPL

None

Behavior

On an ESP32-S2 device (Fun House in this case, but on others as well) without TinyUF2, device behaves as expected.

On the same device with TinyUF2, starting clean from a fresh storage.erase_filesystem(), with either empty boot.py + empty code.py, or some (but not all) combinations of trivial and non-trivial boot.py + code.py, when reset the device will display the Blinka icon, then go into an apparent loop where nothing else is displayed (regardless of any print statements in boot.py) and the violet status lights and the red LED will flash every second.

To recover, go into safe mode and delete or rename the boot.py file, then hard reset.

Saw similar behaviors on rc.0, but not on various beta versions or prior.

UPDATE:
Further testing indicates that the presence of TinyUF2 does not seem relevant, the issue can be triggered with or without TinyUF2.