A few days after adding an initial list of child workpackages to a given work package, any new child created is put at the TOP of the children list (see attached image).  How can new children be appended to the END of the list instead?

I've tried various sorting options without success.  It's very important that we use the tree-view of the work packages, so any sorting of the view unfortunately flattens it out.

Apparently this issue is discussed in Feature OP-4621, but it's incomplete.  I agree that sorting a package list then expecting the sort to remain when switching to hierarchy mode is selected would be confusing.  However, the ID's should be (at least) sorted NUMERICALLY in the tree view, NOT TEXTUALLY.  I'm simply suggesting sorting by PARENT ID, then child ID numerically instead of as strings.

Are you still having this issue as of version 8.3.1? When I first read your description of the issue, I thought I understood it, but I tried to reproduce it, and I don't get any of the bad behaviors you're referring to.

Yes, it's still happening in 8.3.1.  Simply create a couple of work packages, each with 3-4 children.  When you switch into hierarchy mode everything looks  fine.  However when unordered start dates are set for the children, the order in the hierarchy remains by ID, so the gantt chart looks like crap.  Worse, if the childrens' IDs cross a decade, e.g. 98, 99, 100, 101, then the order they display is 100, 101, 98, 99 because they're sorted as text, where 1 precedes 9.
All I want is to be able to sort within the hierarchy view.  We're looking at the source code now to implement it ourselves.

Sorting within hierarchy view works fine for me. This was addressed in the 8.3 release.

bug ticket

PR addressing the issue

I was running 8.2 at first, and the lack of sorting under hierarchy mode was driving me nuts. Are you 100% sure you're running 8.3.1?
It took me a little while to find where OpenProject reports what version is running -- it's /admin/info.

I was wrong.  Even though the OpenProject info showed 8.3.1, I think I may have switched to the wrong browser tab (test/dev/prod) running 8.2.  When I upgraded prod to 8.3.1 just now, I see the issue is gone.  Thanks!