Doesn't feed from left boob

My LO is 4 months ebf and doesn't want to feed from the left boob. He turns his head away, won't latch and cry. I pump and feed him he doesn't want the bottle too. Just the right boob. I'm worried he isn't feeding well. He had been doing it for a while. Sometimes feed on it when sleeping if I get lucky.

I have tried switching positions to trick him to feed but he is too clever.

I'm worried he isn't feeding well. Don't know what to do.