[zxaura1]

@zxaura1,

I mean no disrespect but, how on earth could changing your resolution from 2160p to 1080p, while KODI is open, and then back again, screw up your entire system so bad you have to format and start over?

Why would you install v.18 "over" v.17.6?  We just discussed the importance of backing up existing v.17.6 and installing a fresh v.18 for testing with you and others in detail by multiple users one page back?

Sorry this happened to you.  I don't know what to say...

Dear @brazen1 sorry I’ve been misunderstood. No, this procedure didn’t mess up my system and of course it’s not your fault!
First I renamed userdata folder and started to install v18 nightly x64. In the middle of this procedure Kodi discovered the old version and asked to install in the folder Program Files(x86). So I renamed userdata back and installed v18. I had already decided to do a format for other reasons which I will explain. Then I made your test and the results were as above.
The reason I formatted was that the new card 1050Ti had problem with refresh rates. For example when I selected 23Hz in NCP the card reported 24Hz (as my Receiver shows). But it was actually 23Hz because when tested to play with Kodi video player a movie (23.976Hz of course) there was no refresh rate changing on the TV. Maybe this wouldn’t be a cause for format but when playing the same movie with MPC-BE refresh rate changing happens on TV.
Also another problem was that the PC crashed and black screen appeared when switching the TV off and on again.
Finally, after the format nothing changed and I installed back my 1060 card. So it appeared that the 1050Ti is a faulty card because now everything is more than perfect.
So, after a fresh install of W10, nVidia drivers 385.28 and latest KODI v18 nightly everything is working unbelievably perfect, EXCEPT if I enable 3D in NCP. Then not only starting an HDR movie with MPC-BE takes ages and sometimes fails, but sometimes ether crashes or giving no proper sound.
Another thing I noticed is that without adding any display modes to MadVR, 3D MVC movies play perfectly!!! And when stopping KODI is in position functioning great. If I set stereoscopic 3D in NCP or 3D display on windows display settings, then everything is messed up. Not only playing HDR has problems but when closing MPC-BE then KODI goes in the known small window in up left corner, as yours.
Sorry for the long post, but I wanted to share my findings to help