RE: UP2414Q won't reliably resume from sleep or reboot using mDP to DP cable
Thank you for the quick answer Chris but I am afraid you are not quite correct. It is correct that the problem arises before loading drivers - but that is also a problem that other users have stated so far.
More importantly, as I said in my previous message I use MacPro not mbp (MacBookPro) as you say. It has Thunderbolt 2 port which is also a Mini DisplayPort 1.2 (the vice versa is not true though) and the Dell monitor is set to dp1.2.
So the problem is there. If I use an adapter - a Mini DisplayPort to vga or dvi and attach an older monitor (also dell) it works like a charm, always.
Shall I go on and test again with my HP Elitebook workstation? I used the monitor also with that laptop (also supports dp1.2) and I also had similar problems (although much easier to resolve since the laptop has its own display to default to).
I mean the wake-up problem with this monitor is real. Now that I had enough of it (hardresetting the MacPro or having a spare old monitor at the side with mini dp to vga adapter so that I can shut down properly) I am willing to go all the way to test and report in a way that you could reproduce the problem.