Multi-Monitors: Locking machine moves windows to different monitors I am using a macbook with two external monitors.  Frequently, I lock the computer, my windows are on a different screen then when the computer was locked.  

For example:


Open PyCharm on monitor #1
Open Chrome, iTerm2, etc on monitor #2
Lock computer
(Maybe wait for a few minutes?)
Unlock computer
Windows are now randomly distributed.  This may mean any of the following: 


Windows are reversed - PyCharm is now on monitor #2 and everything else is on monitor #1
All windows are on monitor #1
All windows are on monitor #2



There seem to be multiple variants of this problem.  It seems to occur both when the lid of the laptop is open and when it is closed.  I haven't used the computer with a single external monitor, so not sure if the issue occurs then.  One related issue is that sometimes it will not recognize one or both of the monitors and I need to unplug/replug the monitor to allow the computer to recognize the monitor.

Info on my system:



And monitors:



(Maybe related) Mission Control:
I had the same issue and changing the cables / adapters fixed it.
My 2 monitors were plugged through an hdmi-hdmi cable going in an hdmi-usbc adapter. Changing one of these to an hdmi-usbc cable fixed the problem.