I did not expect this to stymie me today.

No matter how much I try to drag, I can’t resize the comment. What?!

Solution

Show the comment. Really. After I show the comment, I can resize it. I can’t resize the comment while I’m editing it, but I can resize the comment while I’m merely looking it.

Annoying. I’m going to forget this. When I’m editing the comment, the icon suggests to me that I will be able to resize the comment box.

As usual, I published this so that I would find it when later I have the same problem.

Reference

OpenOffice forum, https://forum.openoffice.org/en/forum/viewtopic.php?f=9&t=63642. It looks like LibreOffice has the same behavior.