5 months old and seemingly sleeping a ton?

Hi all! Off the top I’ll say I am more than happy to go to the vet - just wanting to see what others thoughts are on the matter.

Little man is 5 months old and has been settling in with me since the end of January. He has a ton of floor space, substrates, clutter, forageables, a giant wheel, and overall seems to be enjoying himself!

The only thing is that he is getting up and being active for shorter and shorter spurts. He started out getting up around 9pm and staying awake for 7 hours or so. Slowly he’s started waking up later - 10pm, then 11pm, then midnight etc. As of last night the camera only showed activity from 2:30 to 4:30!

What’s strange is that other than not being above ground much, his behaviours seem normal. No concerns for eating or drinking and he’s definitely not moving slowly on camera. He does seem to be a bit of a digger, so my only thought is that he could be spending more time renovating underground and not literally sleeping for 22 hours a day like I’m afraid of.

If this is just extreme ghost ham behaviour then that’s absolutely fine. I just wanted to get some insight in case anyone else had experienced something similar.