A2DVI PiPico problems

Hello Friends:

Perhaps someone out there has some advice.  I am building a couple A2DVI boards, v2.0.

I have one working card, but the others are having issues with the PiPico, specifically accepting the firmware. 

These are PiPico 2040 boards and not PiPico 2.  They are genuine PiPico boards (at least they are marked as such).

I am using the proper firmware type when uploading to the Pico.

I have tried a couple PiPicos and they all flash SOS with any version of the firmware beyond 0.7, the original firmaware. (although I have not tried v0.8)

I have one PiPico working. It is a PiPicoH. But the only difference between a PiPico 2040 and a PiPico H 2040 should be a debug plug on the opposite end of the board from the USB.

I have tried Mac and PC, I have tried different cables, I have tried different USB ports, I have tried flashing the nuke file to clean the board completely. I have tried flashing it in and out of the A2DVI card.

Frankly I am perplexed.

Anyone else run into this?

Thanks in advance,

Mark