Window Buttons / Tasklist sorting by Group Title & Timestamp is broken
I have "Group windows by application" checked with a sorting order of "Group title and timestamp".
Up until 4.18, that worked fine, exactly as I wanted. The oldest window was at the bottom, making it easy to select. I rely on this to find my most commonly used browser windows, new windows tend to be transient while the ones I use the most stick around and end up at the bottom of the list.
When I upgraded to 4.18 in January, the oldest window moved to the top of the list, i.e. the sort order was reversed. An annoying change, but I got used to it quickly enough.
Today, after upgrading to 4.18.2, the oldest window moved back to the bottom of the list. OK, fine, I can get used to that again (in fact, I prefer it - although, really, there ought to be an option for Ascending vs Descending sort for the timestamp. And probably for the title too).
So far, so good.
The problem is that any new windows are placed below the oldest window - so the more new windows I open, the harder it is to find that oldest window. It may as well be random. It's certainly not ordered by timestamp.
This is probably a leftover from when the list was sorted with oldest at the top - it makes sense to add new windows to the bottom in that case. When sorted with oldest at the bottom, though, new windows should be added to the top.