"I’d never tested it on MacOS myself, but I couldn’t see any reason why it wouldn’t work. I told this person that the problem was surely on their end."
Her reaction to the report says all you need to know about why people don’t report things.
It's a self-reinforcing feedback loop of communication failure: users don't report even the most obvious problem; maintainer assumes that if such a problem were a general issue for all users it would have been reported by any of the previous 100 users - but it hasn't been so the one user that actually takes the time to report it must be holding it wrong.
Also, "I couldn't see any reason why it wouldn't work" seems to me like a very dangerous assumption.
I personally try my hardest not to declare that X works on/with Y until I've seen it with my own eyes. Not 2 computing environments are the same, and everything receives updates all the time.
Her reaction to the report says all you need to know about why people don’t report things.