Hi Kodi forum,
My setup :
Lg 49ub850v 4k tv. Link to LG tv here : http://www.lg.com/uk/tvs/lg-49UB850V
Denon Avr X3200W Sorround receiver – Denon connected to Lg tv with hdmi in ARC port hdmi version 2.0 HDCP 2.2.
Link to Denon here : https://www.denon.co.uk/uk/product/homec…/avrx3200w
Nvidia Shield Tv Pro 2017 – Shield connected to Denon with hdmi in hdmi 2.0 HDCP 2.2 port. Bought a few days ago.
Western Digital Wd My paspport usb 3.0 External harddrive.
Kodi v17 app downloaded from Google Play store.
Issue :
Im almost 100 % new to this Shield Tv Pro, i did some reading about it on different forums before buying it, but not enough reading i guess.
I have installed Kodi from the play store, and all my movies are in MKV H264 Remux, and the size of each file is about 25-30 GB. When i playback the movies in Kodi from either the internal harddrive or the external usb 3.0 harddrive, the playback aint 100 % fluent, its not all the time but its enough to be anoying. I dont now the exact expression for what ” aint 100 % fluent means ” in nerd expression, but the picture chops a little tiny bit sometimes, but without loosing the sync with audio or anything. But when i unplug the Shield and then connect it directly with hdmi, to the LG tv, i can set the resolution in Shield settings under display, to 1080p 59,940hz, and all of the sudden i dont have any issues, and now fluent playback 
Hmm can anyone tell me what settings should be made, to have the same fluent playback experience, when the Shield is connected to the Denon receiver ?
I tried in Kodi to set the adjust display refresh rate to Always, but that didnt help.
The same has been tried with Spmc app from Goggle Play Store, and it seems like Spmc is doing best, but not good enough.
You can probably see that i am new to this forum, so what ever info that i missed to provide, i hope you can bear with me, and tell me what you need.
So can anyone please please help me 
Best regards
nonerdhere
Edit : once again i saw the movie that i saw yesterday, and now i set the resolution to 1920x1080p, and the refresh rate to 23,98, this helped a lot, but sometimes i experience the problem anyway, not often but occasionally 
And now that i have seen it again, i found a more appropriate way to descripe what the issue is. I experience it like a very very short delay in the picture, and like the picture catches up again.