I am activating my crystal ball, my crystal ball is pointing to the possibility that a) you are doing something wrong, or b) the Pico2 is experiencing a mental break down, or c) the PicoCalc is showing intermittent amnesia.
A well proven method to dig into difficult problems is to go back to the base line and confirm that everything is working as expected/promised. In this case use the original Pico1 board and flash “firmware/UF2/PicoCalc_PicoMite_v1.uf2” from the original SDCard . If this works then take the next step and use the Pico1 with the UF2 file PicoMite_PICO_V6.00.03_PicoCalc.uf2
If all successful then you can try your Pico2W with WebMite_PICO2W_V6.00.03_PicoCalc.uf2
If you are still unsuccessful it might be time to contact the supplier of your hardware to get replacements.
One important tip: After flashing the Pico do NOT immediately remove the USB cable, wait for the LED to light up. If the LED does not come up then either there is a problem with the transfer, the LED is broken, or board does not allow the LED to switch on, in all those cases wait at least a minute for the processor to complete the transfer.
This is the danger if you are accessing a repository that is not really intended for the general public, this repository is used by me to allow a few users to evaluate the changes I have made to the sources with the intent that these changes are sometime taken into an official release.
At this moment I am not very happy with the current situation (not referring to you) because a few things have happened that give me the impression that some of my material is being noted and carried over into the official development channel but there is no return at the moment and we/I can not produce an acceptable PicoCalc release equivalent to the latest PicoMite versions.
It would be rather simple to implement this in the picomite code but there are many good reasons why this should not be done. When you read the posts on backshed you should be able to see why it is problematic to make extensions to picomite. I can do it in a few minutes but there is the problem of publishing and maintaining the code AND I have restrict my changes to PicoCalc adaption only.
Please be aware that the backlight handling in the bios is flawed.