Locked in full screen mode

After a recent Windows 10 update, when I open SketchUp it is now in full screen mode and I am unable to exit full screen mode. Any suggestions would be appreciated. I have searched the Community data base without success.

Although, it is not clear what “full screen mode” means, since there is no full screen mode of SU. However, perhaps you can try this:

Sorry, but what do you mean by “full screen mode”?
Since your profile says Pro (subscription), I suppose you aren’t using the Web version.
In which case, I can’t help, unless you describe what you mean.

The Minimize/Maximize toggle takes you between full screen and non-full screen mode. When I first start up SketchUp 2020 Pro, the SketchUp window occupies my entire monitor window; hence, full screen. When I toggle between Maximize and Minimize, SketchUp goes from full screen to what I thought was in icon 5/16" tall by 1 1/2" wide. Does that sound like a useful size? The light bulb finally went off that I had to grab a corner of the 5/16"x1 1/2" window and stretch it to whatever size I want. Problem solved. Is there a SketchUp setting that says minimum window size shall be …

Thanks for your comments.

The first suspect for the thumbnail-size SketchUp window is yourself. The second is Windows. At least for me windows are sometimes resized in a half random way especially when I switch monitors. Also, Windows might have an arcane keyboard shortcut that caused it when you hit it without noticing.

Windows NT had a keyboard shortcut that turned your display upside down. I used to spend a lot of time looking for it when a coworker had hit it by accident and was thinking that his/her computer had broken. Some people also used it as a practical joke.