How new Philips 4K display made my 5K iMac useless

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Few months ago I got Philips BDM4350 4K display. I was very excited and expected it to improve my productivity. How mistaken I was!

1. The display has extreme ghosting problem. Even 10-15 minutes is enough to leave ghost of static screen parts like menus and similar for a long time. But this is not a iMac problem.
2. The display has power saving feature that cuts of the power when screen is idle. Great for the environment, however every time I wake my iMac all my windows are moved to iMac display and few seconds later iMac recognizes Philips display as it was just plugged in and rearranges my windows back. This is very annoying, however not the worst problem yet.
3. Often (like 1 every 5 times) when I wake up my iMac from sleep it fails to bring up internal 5K display. External 4K wakes after several seconds as above, however internal display stays black. The only way I know to bring it back up is to reboot whole thing.
4. And finally sometimes no screens wake at all and I have to reset with power switch.

How annoying is that?!

If I could fix waking problem I would be partially satisfied. Does anyone have any idea what to do?

My iMac 5K is late 2014, everything frequently updated.

 

[looking4anotebo]

Philips is well known for producing garbage that doesn't last.

 

[bbrks]

Woooww, now that was a big help post

 

[goto]

Philips is well known for producing garbage that doesn't last.

Well, possibly yes, however that is not the case here.

 

[theluggage]

Often (like 1 every 5 times) when I wake up my iMac from sleep it fails to bring up internal 5K display.

I had this happen once a week or so ago and thought it was a one-off - mostly it has been working fine - but it has just happened again - so you're not imagining it. I've got a Dell 4k and a Dell 1920x1200 connected (and I'm using Pluggable USB-C to DisplayPort cables) so it's not Phillips' fault.

Unfortunately its too infrequent to really troubleshoot :-(