I think that if you don’t get stellar interview, it doesn’t mean they personally dislike you. Just that they think some things need improvement. But it’s not personal. I don’t think it’s mixed message or anything to do with how they feel about you. In fact they might really like you even if they give you a bad review. Also negative review doesn’t mean you aren’t doing good job the very next day. Or from then moving forward

Years ago we had a guy at work who literally couldn’t do his job to save his life. Not your situation, just as an example. . He was on an improvement plan when he had to do monthly reviews to show improvement. He didn’t. He was asked to leave or he’d have to be let go. He was the nicest guy though and everyone including administration really liked him. There was nothing personal.

I am not saying it’s your situation, I am just saying that getting negative review doesn’t mean they dislike you or can’t be friendly with you or can’t compliment you when job is well done. In fact it would be unprofessional of your boss to act all mean and grumpy or not appreciate when you do a good job just because he didn’t give a good review. It’s not a social situation