4 year old Cat suddenly afraid of my boyfriend

My boyfriend and I have been together for over a year and have been living together since January of this year. Recently though, within the last 2 weeks, my cat has been acting extremely afraid of my boyfriend. He will hiss and run away or cower. I’ve been around and we have cameras so I can see he hasn’t don’t anything to hurt my cat, but it’s like my cat doesn’t recognize him anymore. It’s gotten to the point where he’s starting to hiss at me and be afraid of my own presence. I’m not sure what’s going on? Is it possibly something medical? My boyfriend has been nothing but sweet to both my cats, buying them toys, expensive foods, giving them treats and playing with them often and has even won over the affection of my other more shy cat. I’m not sure what to do and we’re getting a panel of bloodwork done in a week to see if it’s anything medical. He can’t seem to get relaxed when my boyfriend is in the room. However, he will go up to my boyfriend when he’s asleep either in bed or on the couch. Any recommendations? This is a 4 year old cat that takes medication daily for his anxiety and temper as it is.