Trying to Understand his Mania

I know i made a post previously about my situation but im trying to seek some clarity on his thinking process. From reading other people's discard stories, i understand that their SOs experience mania and suddenly become very cruel and can cut off communication on a whim.

My partner (30M and diagnosed) has never cut me off before, in our one year together. I've seen him go through a mild manic episode (he told me he was manic), but even then he stuck with me and promised me he's mine. I have tolerated being gaslit by him because I know his condition and wanted to be understanding out of kindness, even though it hurt me and he couldn't see it.

But right now, he's working himself to death, he's functional (from what he told me the last time we called), he's applying to grad schools, doing several projects at once, and keeping himself super busy. This is also why he said that all this time when he's been cut off from me, he didn't feel like he was missing anything at all, even though previously he wouldn't be able to go a day without talking to me.

But all of a sudden it's so easy for him? all of a sudden what we both felt was a rare and beautiful connection, he says it meant nothing and he's completely fine without it?

how is he manic and still so functional? is he avoiding his feelings? should i wait around for him to come back because i love him and care for him so much