The selected merge method (merge) is not allowed

Getting the following message on multiple different PR’s when trying to do a squash and merge:

The selected merge method (merge) is not allowed.

Note that squash and merge are enabled for the repo and I am admin so it shouldn’t be a permissions issue.

It’s possible someone turned off “Allow merge commits” in our settings but I guess there is no way to tell who and when that happened. Squash merging is still allowed which is what I was trying to do.

Checking the “Allow merge commits” seemed to fix it. This is not desirable, however, because we do not want to allow straight merge commits, only squash and merge or rebase and merge.