For the record, it's failing silently, too, showing e.g. "There aren’t any open pull requests." even though there are dozens. That's pretty bad, this will definitely mislead people.
It’s also massively more performant
Breaking buttons on the website is one thing, kinda, but Enterprise used to mean a certain degree of robustness and seriousness in product management.
The bug only affected repos using merge queues AND squash/rebase merging (instead of the default merge commit)