My chin is making small noises from his nose I think

It started a few weeks ago and I thought nothing of it. He is still drinking and eating normally, normal poops. I did have to separate him form his mate since she was eating all the food. He seems lighter and a little skinnier since then and not as active. He makes strange sounds that sound like it comes form his nose. Like its stuffed, almost like a small squeak from his nose. He's active when I take him out for play time but in his cage he might run for a bit and then just stay in his...

My chin is making small noises from his nose I think