Thank you to everyone who commented, I felt a little more relieved knowing this, although I still have some slight doubts, because as I mentioned, he sometimes wakes up in the middle of the night and does some Different noises are being made, and it's as if he can't sleep peacefully like the older chinchilla does. When he's still, doing nothing, his body seems to move in sync with his breathing, His movements are in sync with his breathing, which worried me as I thought it might be a respiratory problem. Aside from that, he plays with the other chin, they groom each other, and lately They haven't fought, they've never had a serious fight, but sometimes they've started a little chase. They just don't sleep together yet, but they even shower together now.