Accidentally hid all the columns within a folder

I somehow accidentally hid all the columns within a folder.

I've gone to tools, clicked on columns&Categories, and selected the hidden columns, clicked on the eyeball and then save. In the background I can see it reappear, but when I click the x to close the window, it reverts back to being hidden.

Am I missing a step?

Thanks

Hello,
You've probably just closed the folder. Tap on the folder icon in the gradebook to make sure it is open. If you still can't see those columns you should open Tools > Columns to make sure they are not hidden this time.