I got a trouble...
My rig have 2 RX560 + 3 RX470 and 1 Vega.
HBCC can be set to en/dis , but slide is fixed:

Whatever how I change the HBCC en/dis, in XMR-Stak-AMD, hashrate looks like not enabled.
What going on?

Win10 / Blockchain beta driver / 8G system RAM / 32G VRAM
Vega56 w/vega 64 Aircool bios
All other things looks like normal.
Thanks
try to remove 2 rx 560 cards from rig.
With current amd drivers there is a problem with HBCC for Vega if you have more then 4
AMD cards in the rig.