P: LrC 15.1 Navigator live preview not working when hovering presets

Hi

When option "Enable hover preview of presets in loup" is ON I see the preview of present in main window end in navigator small preview window. Bad if I disable in preferences "Enable hover preview of presets in loup" I can't see preview of the preset in this small navigator window. I think that before last update it was working correctly and I see the present preview only in the small navigator window. 

Can you help me to fix it? 

I did lightroom references reset starting LR with shift and option keys pressed. It doesn't help. 

I use MacBook