I'd imagine it's worse now, but I was sweating blood during my AP tests 8 and 9 years ago.
If I were told by College Board that they messed up, they couldn't verify what I did, and that I'd have to take the tests again, I'd be livid. I would feel incredibly screwed.
On top of a pandemic, new test guidelines, classes going remote (and the associated growing pains), studying for the test, and some extra stress-studying because some classes inevitably were taught ineffectively at the start of remote courses, now some people have to take the test all over again? That's a lot for a most people but especially high schoolers