I'm trying to figure out why my content type isn't applying, (stays a 'None' but the content threshold should trigger) then found out my folders are auto-locking themselves when entering the folder.
Looking at the source of the current format and it doesn't know why either. ¯(°_o)/¯
Layouts and Styles can also apply the format lock, if they are configured that way.
But a script does seem more likely, as I think there were discussions about applying the format lock via a script recently. Maybe Search results format lock
It's also possible it's both: a script may have turned it on and you then saved the default lister / layout / style (to save something else, without realising it was locked) so it's locked again when they're loaded.
You're right, I did download ThioJoe's script but I had deleted it.
I found the problem was that I had saved the lister, and set as default while it was locked. Sorry about that.