You are correct. I prefer Metro M but have switched until there is new code for it.

Is this with Metro M skin only?

I have just tested and see the issue too, so it looks that https://www.ventismedia.com/mantis/view.php?id=17858 hasn't been fixed properly, I've re-opned it.

I can replicate this way:
1) Select a playlist with columns like this in the 'Media Tree' : https://www.dropbox.com/s/47ep8enwq7h0186/Screenshot%202021-06-24%2013.13.32.png?dl=0
2) Switch to another playlist: Columns get a few pixels wider
3) Switch to the original playlist: Columns gets a few pixels wide again

I'm having the same issue, however mine is anytime after restarting the computer and re-opening MM5, the column widths are reset to an extremely wide default.

Is there any way to get the column widths to automatically size to fit the widest item in the column?

Actually the problem is not solved. The column widths used to change every time I changed playlists. They no longer do that. But the column widths still change every time I close and reopen MM5.

I downloaded 5.0.1.2418 and the problem appears to be solved.

Thanks

Please update to build 2416 as it includes a bug fix for this: https://www.mediamonkey.com/forum/viewtopic.php?f=30&t=86639&sd=d

v5.0.0.2338

Metro M (Classic)

Which build (Help > About) and Skin of MediaMonkey 5 are you using?

How do I get the column widths in MM5 to stay fixed at the widths I establish? MM4 never behaved like this.