Unsaved settings in "Columns Configuration..."

The folder “Inboxes” does not store / save the settings in “Columns Configuration…”, from one session to another. I tried 3 times. I think it’s a bug.
I use eM Client version 9.0.1708 (2cfb4a5).

I presume you mean “All Inboxes” in Favourites at the top left columns configuration.

If you do, that one doesn’t save like the others.