BUG / REGRESSION: Library columns no longer remember chosen width

When I close the Library it looks like this:

When I open it again it looks like this:

Notice how the Rank, Type, and probably Title columns have become wider, and that the My Tags column -- which I desperately need to see when tagging -- is no longer visible.

Since tagging uses so much RAM that it often takes me 3-5 sessions to tag one single collection, it is very annoying to have to start by changing the widths every time.

I imagine there's a good chance this is related to BUG: TOC's no longer remember chosen width. (I've been aware of this bug for at least a couple of weeks, and I didn't have anything to tag for a while before that, so there's a good chance they appeared at the same time, even though the reports are several weeks apart.)

EDIT: I just found a screenshot of the Library columns taken Aug 18. I now remember taking that because I was already suspecting they didn't keep the width, but I never found the time to follow up. So the regression has indeed been there for a while.