Sorry, server key has changed

In our case, we’re seeing “Sorry, the server key has changed” (although it never has) and when clicking accept, we get

Something went wrong.

The operation failed with the following error:
The key should be a valid openpgp armored key string.

The odd part is that this only happens when opening the website, but signing in to the extension widget still works fine.

I checked that, where I’m seeing this, I’m running 3.6.2, I have other workstations where the error doesn’t occur. Regardless, I’ll try rotating the key as suggested.