Mac Multi Monitor Misery

Update – I haven’t updated Macbitz in a while and it looks like my past two posts were also about multi-monitor irritations. What can I say other than “Apple – it’s still a problem!”.

I like macOS. Been using it since 2008 when I bought my first ever MacPro – the tall aluminium (or aluminum depending on the side of the pond you’re on) and that machine is still running today, although as a headless storage machine now. No today I’m sporting a late 2013 27″ iMac and as a legacy of my days in IT it has two external monitors connected to it. Both 27″ monitors, both running at 2560×1440 and giving me a huge expanse of things to distract me.

It all works pretty well, OK the Iiyama monitor which I wrote about some years ago is still a pain with backlight bleed you wouldn’t believe and a very dodgy power switch, but the Dell 27″ monitor more than makes up for it. My only issue is that a 3-monitor setup involving an iMac seems to be a pretty rare thing as far as Apple is concerned, so much so that they probably never test this scenario when developing new versions of macOS. Starting with Leopard back in early 2008 right the way up to Mojave some ten years later, support for three monitors under macOS has been flakey at best! Let me explain. Every time there’s a macOS upgrade, be it a completely new version or just a bugfix update, macOS takes it upon itself to keep things exciting by swapping my monitors around. So what was Display 2 becomes Display 3 and what was Display 3 becomes Display 2. This means that every app that I have assigned to always open on the Dell monitor suddenly starts appearing on the Iiyama monitor and vice versa. It’s then a painstaking task of reassigning specific apps back to the correct monitor. I could just shortcut this swapping the position of my two monitors in System Preferences but the problem there is that as I move my mouse off the left-hand edge of the screen to move it to the Dell monitor on the left of my iMac, the mouse pointer would actually move to the right and appear on the Iiyama monitor which is just confusing. Doubtless macOS has its own internal record of where monitors are and for some reason when an OS upgrade happens this record gets wiped and the old switcheroo happens.

Moving on – I don’t change my wallpapers much but one thing I do is to have the same wallpaper across all three monitors. However… when macOS upgrades happen, the wall paper on one or more monitors will be reset to what it was previously. By that I mean if I have a picture of a sunset on all three monitors and I change it to a different picture, when macOS is upgraded from say 10.14.1 to 10.14.2, the wallpaper reverts back to the sunset picture. I don’t know if macOS retains a history of what wallpapers you’ve used but if it does then it is jumping back to a previous entry.

As if that wasn’t enough, the same happens for screensavers. Perform an OS upgrade and you’ll be treated to the previous screensaver you used.

Anyway, moving on from the trials of OS upgrades, there are a few problems that just manifest themselves on a daily basis. The first is random screen choice for apps where I haven’t manually assigned them to a specific monitor. Now one would assume that when opening an app it would default to opening on the last screen it appeared on, so if Spotify was last open on the Dell monitor then when reopening it, Spotify would again open on the Dell monitor. Not so, it will revert to opening on the iMac or sometimes the Iiyama monitor. The only solution is to manually assign it to a particulr display (then enjoy the fun when that gets reset by an OS upgrade).

And so on to my final bugbear… the Dock! Now it seems that macOS has this handy feature where the Dock will move from the main display (my iMac) to a different display so that it is close to hand when working on a different monitor. Great, however the trigger for this is completely random! Sometimes all I have to do is move the mouse from one display to another and without so much as a click the Dock will jump to that monitor. The only way to get the Dock back to Display 1 (the iMac) is to:

  1. Move the mouse pointer up to the menu bar on Display 1.
  2. Click on the menu bar on Display 1.
  3. Click anywhere on the wallpaper on Display 1 (clicking on an open app on Display 1 doesn’t work).
  4. Finally move the mouse right to the bottom edge of Display 1 which point the Dock will return to Display 1. Why it is necessary to go through this rigmarole to get the Dock back to where it was when macOS moved it to another display merely because the mouse pointer was on that display is a complete mystery to me! Actually what would be nice is if there was a System Preference under the Displays section where you could tick a box that says ‘Do NOT move Dock when using multiple monitors’.

I have submitted bug reports to Apple but I dare say the number of macOS users out there using more than two external monitors with an iMac is fairly small and thus these bugs don’t rank high on their list of priorities. Shame really because macOS is supposed to be the pinnacle of ‘Ease Of Use’ when using a desktop OS and these flaws just detract from the overall experience.