Woohoo! Turns out I was able to recover the boards with a little "manual intervention", but the workaround is really weird. I basically run a certain step that sets the necessary magic bits twice. The first time (done automatically) doesn't take, but the second time (done manually by me) does take. I still have no idea why this steps suddenly stopped working, but since I recovered the boards, I can now get some sleep this weekend.
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