Catalina 10.15.1, MacVim 8.1.2234 full screen before sleep, full screen is broken on wake

Describe the bug

After waking the computer up, MacVim which used to be full screen is no longer full screen. The "full screen window" where MacVim is supposed to live is still there, but the MacVim window itself is not full screen, and exists on a Desktop "window". I'm not sure of the correct term here, but by "window" I mean the full screen switcher which appears at the top of the screen when in what used to be called expose mode.

The MacVim window is mostly unresponsive -- keypresses do not have any visible affect, and clicking the window doesn't either. When using the macOS application switcher, the "full screen window" is activated when attempting to switch to MacVim, but the screen is black.

If only one MacVim window is open, sometimes the green full-screen button works and will put the window back. Sometimes not. I believe that when multiple windows are open, the green full screen button never works.

Often the only way to get back to a working application is to force quit macvim.

If the terminal with which I launched MacVim is still open, a message like this is printed:

2019-12-23 05:57:59.389 MacVim[10882:9934680] not in fullscreen state

To Reproduce

This is a bit of a head scratcher for me, but I believe I'm able to reproduce it intermittently in this way. I see this bug several times a week, but it is not consistent.

• Open a file in MacVim - I usually do this with mvim in the terminal.
• Full Screen MacVim
• Put computer to sleep for a while -- short sleeps don't seem to trigger it.
• Wake computer

Expected behavior

The application should not lose it's full screen status.

Screenshots

I will attempt to take a concise screen recording next time I see the problem.

Environment:

• Vim version 8.1.2234
• OS: macOS 10.15.1 (19B88)
• stock macOS terminal.

I cannot see how it would matter, but my vim config is on github as is my list of plugins

Beginne damit, den sporadisch auftretenden Fehler mit MacVim 8.1.2234 unter macOS 10.15.1 zu reproduzieren: Starte eine Datei mit mvim, aktiviere den Vollbildmodus, versetze den Computer in den Ruhezustand und wecke ihn wieder auf. Vergleiche das Verhalten mit einem und mit mehreren Fenstern, einschließlich der Meldung „not in fullscreen state“. Als erledigt gilt die Aufgabe, wenn MacVim nach dem Aufwachen reaktionsfähig bleibt und den Vollbildstatus beibehält.