Odd Behaviour?

Hey guys! Sorry for what might be a pretty long post!
This behaviour has just been going on only this afternoon but I'm a paranoid mother and always fret about my baby when they're just not quite acting normal. Especially because they're my first Bearded Dragon. I have a good relationship with the reptile store's owner that I bought them from so I've gotten in touch with him as well, however I'm just wanting to get some more opinions while I wait for a reply.

So my Beardie, Haku is roughly 3 1/3 to 4 months old. Gender I'm not sure about. At first they were sexed as male (which I also agreed on) but as they're getting older I'm starting to think he might be a she as there are no particularly two prominent bulges but at the same time it's difficult to tell. They don't let me hold them in the right position long enough to get a torch up to them either.

To give a bit more background: They're tank correct with every specification recommended (temps, lights etc.), Haku eats 3 meals of crickets (dusted with calcium 5 days a week and vitamins the other 2) a day, but as of late they haven't been too keen on lunch and prefer to just eat breakfast and dinner with maybe some greens in between. I still offer him lunch and take out what crickets he doesn't eat. Haku isn't a huge eater of greens right now, it really depends on the day. Sometimes they will eat all of it without prompting, other days it's all I can do to hand feed him 4 pieces of greens. I also mist and bathe them regularly, I tried keeping a water bowl in their tank for a while but all it does is make a mess and Haku never drinks from it. Haku also sleeps well (lights are out at 8:30pm/9pm and back on at 7am every day).

Just today Haku has started being a lot more active than usual. They're pretty chilled out majority of the time, happy to bask under the UVB light all day. Haku also gets time out of his tank multiple times a day and loves to run around and explore, or just sit on my shoulder/head. It's winter here right now so he hasn't been able to have outside time in the sun.

What is really causing me worry however, is that Haku is digging in his substrate a lot. This is something they haven't done since I got them as a tiny baby when they'd burrow at night to sleep. The substrate I used is pellets of compressed recycled papers. It's what his breeders use for their Beardies and I've had 0 issues with it. Haku is good at spitting it out when it gets in his mouth on accident (which is rare) and the very few times he might have eaten a bit it hasn't caused any issues with being impacted and such. However, for the past... maybe hour and a half now I have been watching Haku dig in their substrate almost frantically. They keep digging even when they reach the wood on the bottom, which is past the paper towel I keep beneath the substrate as well. Haku might stop for a bit and burrow himself down or move to go and bask for a bit but then he will continue to frantically scratch and dig at the wood. They're doing this in the corner on the cool side of their tank. Haku has also had maybe a slight decrease in appetite, they're no where near as keen about being fed as they usually are but it's not like Haku is eating nothing at all, just slightly less. It's really worrying me to see Haku this way as it's just not like him?

I'm stumped on what it might be? There has been no change to his environment at all since I got him, except for the additional stick or upgraded basking rock/perch but Haku was never bothered by them in (haven't put anything new in the tank in a month or so). The temps are normal, absolutely no change there. If Haku is female, I thought they'd still be a bit young to consider that they might be getting ready to lay infertile eggs? I also felt around Haku's stomach and all I feel is the usual soft, squishy stomach they always have. I haven't been able to make out any lumps or anything. Is this behaviour possibly the beginning of brumating, seeing as it's winter and the weather the past week has been pretty cold? or is it possible that they're just bored?

Any opinions/suggestions are greatly appreciated!

At that age it's very unlikely to be egg laying behavior. Burrowing could be boredom or just an instinct to find a secure spot to bunker down for a while. Is he acting sleepier in the past few days? He is a bit young for brumation but it could be temporary and weather related. If it's a frantic behavior it may be similar to the glass dancing escape behavior they sometimes show when they want out of their tanks to run around and explore. This is more common at their age.

That's what I thought too.
Since posting this his behaviour has worsened and is seeming more and more like brumation.
He's been dozing a lot, eating less and less, burrowing more. All the temps in his tank are fine but he's just not himself and always looks sleepy. All of this morning since his lights came on he's just been curled up in corners dozing/ asleep, I took him out to bathe him as he was due for a bath, poop is normal, firm, not dry and there's no blood or anything of concern either.

I have called the vets to get him an appointment tomorrow or the day after though, will get a faecal test done then as well.

Fecal test is a good idea. He is acting like he wants to brumate, is just a bit young for it based on what I've read. Good to see what the vet thinks.

Sorry for a bit of a delayed reply!

So took him to the vet, turns out he had a slight infection, same with parasites but nothing super serious. I suspected that he might have been sick. He got put on one 3 day course of oral medication, another 5 day course of oral medication and then 1 month course of antibiotics, which he is getting every 3 days. He seemed to be making a massive improvement, his energy was up, he was eating again etc. Also got the vet to sex him and Haku is definitely male.

Although, the past 2 or 3 days he's been off again. He's eating little to nothing of his crickets, eats minimal greens and spends a lot of time burrowing and in his hide and staying in there. I'm leaving him to it for now. Temps are normal (80 in cool end, 91 in basking are) but I'm in the process of trying to find a new basking bulb as I red that the ones that give off red light are no good. Just not sure what to get because everyone recommends to many different ones! Haha.

He did start shedding on one of his feet and on his jaw the other day, I gave him a warm bath and most of the skin soaked off. Although... he hasn't shed anymore since his head perhaps does look a little bit more dull in colour though. Is this burrowing, hiding and not eating behaviour possibly a full shed approaching? Just worried about his drop in since he seemed to be making such a massive improvement.

Thank you so much for your help!

The meds may have started making him feel bad. A month of antibiotics seems like a pretty long course to me. Try offering him extra water and maybe a probiotic like non dairy (soy) yogurt that contains acidophilus. That may help him feel a bit better. The red visible lights are no good. The goal is to provide heat and bright white light along with UVB to imitate natural sunlight as closely as you can. There are many good options for achieving this which is why you read different remarks on basking light. I've had good luck with PAR38 and BR40 halogen lights from the hardware store. You may just need to try a few things out and see what works best in your setup.

I did make a post about it with more info here due to my concerns:
(it's got more information regards his treatment and everything)
search.php?search_id=egosearch

I'm working on what you have suggestion, also contacted the vet today. I'll go grab some non-dairy yogurt for him too while I'm out getting his light replaced. Thank you for your help!