XBR850D 4K

Seen A lot of Threads, Read a bunch, but none seemed to fit my bill.
My Sony 4K tv has no issues streaming 4k through youtube, both app,and youtube in Kodi.
on addonThe Silent hunter I can stream The Grand tour 4K NO ISSUES, but go to 4k movies and i Die in buffer. As with Every other 4k addon
I have 1Gb internet connection, though TV only registers 100MB Sad
I have done the Ares Settings as well to try to make it work.

Im out of Ideas.. What else can i attempt?
Could it by the encoding if the 4k movies are different causing buffering?
Im just lost.. Any help would be appreciated.

Thanks,
ppfilbert