The All editing icon buttons lost when entering edit mode for the user profile question got migrated to Meta.SX but deleted there shortly after. I reopened it therefore here and was able to access it correctly afterwards. Also Stefan could access it. However, it seemed that the automatic redirection to the migrated copy on Meta.SX was still active for everyone else which is not a moderator (or maybe 10k+ user).
Basically, I added that comments to the local question and you got directed to the external version of it, while I was not aware of that.
I cleared the migration connection now and I was able to access the question after an logout, so it should work for you. Feel free to accept my answer there to conclude the question officially.