I have the same issues with the narrowing of Layout trays as @bradmdg1.
Floating and pinned trays have the same issue, by the way.
Re-installing with ‘Run As Administrator’ and resetting display scales on both monitors to 100%, as Dave suggested, has unfortunately not improved the bug… 
Although not much hindering my workflow, i wish there was a solution for this, as these quirks are annoying. Any comments are appreciated.
FYI:
I am using the latest Layout version 21.1.332 64-bit on Windows 11, but the issue was the same on Windows10.
graphics card NVIDIA quadro P1000 with latest driver
Layout is usually on a second widescreen monitor (Dell U3415W, 3400x1440 resolution). Same issue though on my primary monitor (Wacom Cintique 16 touch screen)
SketchupPro trays do not have any resizing issues, by the way.
