[r1nkgrl]

What version of MacOS do you use?

I use High Sierra with 3 external displays, and my windows are almost always in different places when I unplug, plug back in. All monitors are the same model (this might make a difference), but I always plug them into the same port they were connected to previously.

One hypothesis I have is the order I unplug / plug in the monitors matters.

Edit: after some quick testing, I can't seem to reproduce any issues while just briefly leaving my monitors unplugged.

The issue I notice the most is that windows get put back on the wrong monitor. e.g. window A from monitor 1 is now on monitor 2 and window B from monitor 2 is now on monitor 1.

[derefr]

> All monitors are the same model (this might make a difference)

It does: your monitors are likely reporting identical EDIDs. Or, to put it another way, your monitor's manufacturer is incompetent. (Which is sadly quite common.)