I have managed to reproduce this issue on Mac 10.12 and Mac 10.13, with Firefox release (57.0.1) and the latest Nightly (59.0a1) build, using the steps provided in the description.
When this happens I have to reconfigure all three monitors and it wastes a lot of time. This is quite frustrating because I have three monitors and I have different browser windows on all three monitors for various reasons. I believe that should be obvious in this case. I have not personally noticed any specific action or commonality being required to trigger the problem, I just know I have to close firefox and reopen it pretty much every day. Often, one of our firefox clients freeze and we'll have to close it completely and reopen it to clear the problem. I work on my profile, and my wife works on hers. I don't log my users out, I simply switch accounts. This occurs with a moderate to high frequency (50%+) (NOTE: NOT 100% reproducible)
HANGOUTS ON MAC OS X 10.13.1 UPDATE
If you then unfocus the firefox window, you will see firefox show an update relating to the action you attempted to do (for example, click back button -> nothing happens -> unfocus -> -> refocus and attempt another action -> Rinse/Repeat
If you try to click anything on the gui, nothing happens. Switch back to User 1 and attempt to use firefox Using the account toggle feature in macOS (typically your users name is on the top right corner of the menu bar located at the top of your screen) switch to User 2Ĥ. You have two user accounts created with firefox accessible on each.Ģ. You are running the newest software release of MacOS (Currently High Sierra Version 10.13.1)