Every character I log onto I have to reset the column count on the inventory, bank, and void storage. I just logged out after fixing one character's bags and when I go to log in again, I will have to fix them again.
I am using Bagnon 8.0.2.

I believe the latest version fixed the issue. Let me know if it did not

This has been driving me nuts as well. There are two issues to this that I'm running into: first, that the addon isn't saving any settings across updates, which is bizarre for an addon that has done that for years; and second, that any settings made are account wide, and not character specific, which is just obnoxious.

I only bother with a main toon, and a bank alt, but these characters do not have the same number of bag slots, and it doesn't make sense for them to be stuck with the same number of collums. I can't imagine the frustration of someone who actually plays alts. For the first time since getting Bagnon, I'm starting to look at other bag addon options.