Puppy acts up when two people are in the house

I'm confused on how to even approach this. All day when I'm at work and Apollo is home alone with my mom, he's good. Perfectly happy in the crate, perfectly well behaved when out of it, a total sweetheart – her words. But when I come home, he changes. He barks if I'm sitting at my computer if he's crated. He will not tolerate being crated for any length of time if I'm home and sitting, even if he's supposed to be napping or he's in time out or I just need a moment of not chasing him around to get something done.

When he's home alone with my mom, he's gentle. When I'm home, he jumps up on her before she can stop him, plays rough, humps and then bites her, etc… and she doesn't even have to be doing anything. Sitting and saying nothing to him. Sitting and talking calmly to him. Standing and walking someplace, paying no attention to him. Walking and talking to him. It doesn't matter; if I'm home, he's very rough with her. He did less of a nip (he's part cattle dog) and more bit her in his excitement a few days ago. Had she not been wearing several layers of clothing, she's positive he would've torn her open. It isn't aggression, he clearly just wants to play, but he plays extremely roughly. And it's only when I'm home. I do nothing to encourage it, obviously. In fact, I'm usually discouraging it and trying to get a handle on him. It doesn't help.

If I'm home alone and my mom isn't home, it's similar good behavior. He'll just lay down and chill out, although occasionally I have to make sure he isn't trying to sneak into the trash can or something. He won't necessarily bark in his crate if it's just me.

I'm baffled. Something about having two people in the house drives this dog batty, gets him overstimulated, something. I have no idea how to manage it. Board and train seems to have done nothing (which I found people say it doesn't only after I sent him to a trainer and paid good money), I've tried to work with him on teaching him that being quiet in his crate is good and will at times get him rewarded with being let out if it seems like he doesn't need a nap.

It's like he acts decently trained when one of us is home alone or the other is in another room or outside, but the instant we're both in the house, it's like he regresses instantly.