Revert a change which was merged with `Squash & Merge`

When a PR/branch has multiple commits and we merge it to master via the Squash & Merge button, we seem to be unable to revert that change later using the Revert button in the UI. It shows the below error.

Is it even possible to Revert (via the UI) a squashed-and-merged commit? We end up having to do it by hand in git, which is more error-prone than using the UI.

I was just able to create a branch with two commits, create a PR from it, squash and merge it, then revert that merged PR: https://github.com/lee-dohm/test-repo/pulls?q=is%3Apr+is%3Aclosed

I’m not sure what might be going wrong with your particular situation, but the base level functionality seems to work. If you could give more details, perhaps we could get to the bottom of it?