Sleep/wake issues with multiple LG UltraFine displays

[Brookzy]

Does anyone find that when waking from sleep with two UltraFine displays connected, sometimes one of them won't turn on?

(My setup is a 13" Touch Bar Pro connected to two 4K UltraFine displays. The issue has materialised on both displays so it is unlikely to be a faulty unit. All software up to date. The only way to fix it is to disconnect and reconnect the display - a full system reboot won't resolve it. The issue occurs in Guest User mode too.)

 

[Brookzy]

Looks like this is a widespread issue with mentions on Twitter, Reddit, and even the Apple Store review page.

A dual 4K UltraFine setup is simply unusable - you have to unplug one each time the MacBook sleeps.

10.12.5 beta doesn't fix it either.

 

[craig1410]

I've not had any issues like this with the dual 5K displays on my 15" MBP so I guess it's either endemic to the 13" MBP or the 4K LG displays.