202 resize window issue.

Weird thing.
I run a detached preview on a second monitor. (pretty much as I have done for years)
I resized the main (made smaller) Sigil, the preview shrunk.
I enlarged the main and the preview shrunk even more.

A few cycles of this and the preview was a postage stamp.
I could grab it and make it larger.

I don't remember seeing this issue before today . W10 did an update an hour before.
Anyone else seeing this?