After reading all this I am thankful all our kids are settling close to us post college and we see them all the time. We raised these kids away from any family, they never really knew grandparents, or aunts and uncles - just knew of them, and it was a big hole. Maybe that helped us be closer as a family, idk. The universe is rewarding us now by having them settle relatively close by and stopping in all the time post graduation. They will raise their families close to each other and I love that. I feel for the OP, I would miss my kids if they weren’t around and it would hurt if they didn’t want to come.
For each kid, the experience at home is different - I give great thought to what each one likes and make adjustments so it is more comfortable for them and they want to be around. Big home cooked meals or going out together, smothering them or leaving them totally alone, being busy or hanging out - find the balance for that one and roll with it.
But this is also a time of his life - it makes complete sense that at this point he wants to do other cooler things. College breaks are the perfect time to explore - no burden or responsibility weighing them down. But time will march on and he will figure out his life and you get more use to him not being around. Maybe next time he comes home, he will love being there and you will find it odd for him to be around and crave your space. It happens.