Resized windows shrink and migrate

[matthewpersico]

Describe the bug
After resizing a window, it will redraw itself, shrinking in size and migrating to the lower right hand corner of the display.

To Reproduce
Steps to reproduce the behavior:
Resize a window. It only happens intermittently.

System Information (please complete the following information):

• Server OS: Red Hat Enterprise Linux release 8.10 (Ootpa)
• Client OS: Windows 10.0.19041.5486
• Xpra Server Version: v6.1-r0
• Xpra Client Version: xpra v6.3-r37166 (g17113d0213) beta

Additional context
Because it is not reproducible on demand, can you give me some information as to getting server logs when this happens so I can send them along?

[totaam]

This kind of bug is almost impossible to debug from the log samples.
What application can I use to reproduce it?
-d geometry,metadata may help, if you include it at both ends.