I had rested and was at 100 focus on a hemomancer. I warded and my focus was around 90ish. I went to use my 10 blood stacks for the empower and it took away focus capping me at 75.
What I Expect to Happen
I expected to use Red Harvest to regain focus up to 100.
What I Actually to Happened
Red Harvest lowered my focus to 75.
Extra Testing
It seems like the focus can go over 75 from sever ticks and rest, but red harvest thinks the cap is still 75 and will lower you to that if you use it. Not sure what the intended mechanic is, but that certainly doesn't seem right.
Edit to add: Red Harvest on myself seems to give focus, however. I will test other enemies. Perhaps it is specific to this one.
Edit to Add: Tested on other creatures. Very reproducible.