Problem with HW h265 decoding

Hello there,

I have a problem with Kodi 17.1 (it was existing with kodi 16.0 before).

When I try to Read 1080p movie, it works great, there is a HW decoding :
[Image: d5ad3d3]
(http://hpics.li/d5ad3d3)

But when I try to play a 4K movie, HW decoding doesn’t work and CPU load reach quickly 100% :
[Image: 1079115]
(http://hpics.li/1079115)
I try to play the same movie with MPC HC and it works great.
What is the solution to use HW decoding with 4K movies ?

NB : I have already force HW decoding in Kodi’s settings).