Just chiming in to do my part.
Got a Framework 16 DIY. I put it all together and got to the BIOS with everything working. Inserted a USB and the keyboard and touchpad stopped working (therefore not OS). I plugged in a USB mouse/keyboard which worked, but didn’t magically fix my problem. I installed Fedora 39, rebooted a bunch of times, and left the laptop turned off but nothing fixed it.
I just reset the BIOS then rebooted and now both work. I am running the BIOS that 16 Batch 1 shipped with.
dmidecode
/* */
BIOS Information
Vendor: INSYDE Corp.
Version: 03.02
Release Date: 01/23/2024
/* */