[mclingo]

forget what people have told you, we need to get you smooth first, you can experiment later with other settings. Set your desktop to 4:2:0 YCBR 10 bit, this should eliminate any bandwidth issues, you wont notice any difference in quality anyway.

The reason you have high rendering is likely MADVR settings and refresh rate, wipe you MADVR settings and start again.  Leave everything at default and go back to COPYBACK decoding.

make sure you've turned off MADVR refresh rate switching and turn it on in KODI DS. If you have the KODI GUI set to 2160p it will upscale everything to that resolution so there is nothing more to set.

Dont forget windowed mode in KODI DS.