My boyfriend takes hours to respond to texts after he gets off work and is always saying he "just woke up" or that he slept. Why?

We only see each other on weekends. On weekdays we both work. After he gets off work he goes silent for hours. Then he'll text "I slept" or "just woke up." He won't even try to have conversation with me. Not like he used to when we first started dating. I talked to him about it before and he said "If I pass out, I pass out." When I leave his house on weekends he doesn't seem sad that I'm leaving and doesn't text me that he misses me anymore. Should I bring it up again or is it a cause for a break up?
My boyfriend takes hours to respond to texts after he gets off work and is always saying he "just woke up" or that he slept. Why?
Post Opinion