There are known issues with going up to and past v3.19 on the 11th gen boards in standalone mode.
Be sure to use the UEFI firmware update method not the Linux or Windows methods. If tinkering with the batch file that calls the firmware be careful because when I had modified it to get it to reflash one side of the main board that it didn’t update correctly it forgot that I don’t have a battery and halfway borked itself into some weird state.
The only fix after fighting with it for a few hours (trying to undo and redo the update) was to rip apart my other Framework Laptop 13, steal the battery from it and temporarily connect the standalone board to the battery and display so I could finally update the firmware.
I understand the firmware team is working overtime trying to keep up with the changes and demand. I wish the commands were broken out a little easier in the script so that if you needed to FORCE it to reflash (because one side said it was updated but never changed the version number) it could finally get past the controllers on each side step and update the main firmware. (This may not be making sense as I am typing it)
Essentially, the standalone controllers should be easier to update than they are. The scripts may be missing or faulting on a check and it jams up the whole update.
Basically, more testing with standalone setups before BIOS updates are released is probably more important as time goes on since lots of users are repurposing mainboards for other projects and the barrier to update the firmware easily is frustrating.