New Beardie Mom here, having some curious issues...

Hi all, I am new to beardies. Previously only a mom to warm-blooded pets
Anyhow, please forgive me if I'm posting in the wrong place or anything, but I could use a little help!
I agreed to take on what I was told was a four year old male beardie. I heard about him through an old friend, he belonged to the family of one of her coworkers and she was told by this woman that they were needing to get rid of him. Well, as she had always done in the past, and out of care and concern that he would end up for free on craigslist or worse, she suggested me and connected me and the previous owner. Are you with me so far? Lol I would like to apologize in advance for this lengthy post...
ANyhow after a couple months of wishy-washyness, she finally dropped off the beardie at my home. It was explained to me that he was purchased approx four years ago for her son, who is now a full blown teenager and cannot be bothered with pets. So, he became neglected and lost in the shuffle. SHe told me he eats apples and romaine, which by that point I had done my research and knew was not nutritious enough but I bit my tongue. She told me he also eats superworms, crickets, hornworms... and her son who came with her told me *gasp* yeah and if you catch any spiders or flies or whatever he will eat those too! Jeez louise. Don't worry, I had already read everything I could find on caring for my new family member, so apparently I knew than they even did!
Anyhow fast forward a little... she went MIA after the drop-off, I had tried to get a hold of her with a few questions but received radio silence. I guess they were just over it. But now here I am, never having had the pleasure of living with a beardo, and I'm just trying to do my best!
I will try the flashlight trick later when I get home to see if I can confirm that he's a boy. So for now, I can only assume.
And here is why I'm posting today...
I have had him for a couple of months now, and he's been lovely. Eats superworms in the morn and any accidental produce they're crawling on. Can't for the life of me get him to eat produce by itself, but if I feed him his worms on a salad he gets some in his little mouth and I guess that's better than none! He'd bask all day, then tuck himself in for sleep around 6 to 7 pm.
But, for about the last week, his behaviour has been totally different! He's zooming around his tank trying to climb the glass or dig out (i have newspaper floor, and one half of the cage has the green reptile felt over top of the newspaper) and he is so restless and constantly moving! Then, by late afternoon, he calms down and is more still until bed. He has also stopped eating his worms every morn. He will still take a hornworm, but wont eat the superworms. He also ate a couple of crickets on the weekend, but left most of them to roam his tank and had no further interest.
All I want is to give him a safe and happy home, but I'm worried I'm not doing a good job. And I'm worried about these changes in the last week. Has anyone ever experienced anything like this? Anyone have any advice?

Seems just like a boost of energy to me, Im really glad you took him in. I cant imagine what care he was getting before, and it seems you've done some good research as well.
My female beardie did that regularly in her old 36x18x18 (50 gall) enclosure, If you can and I'd let him roam around in a safe blocked off room with no other pets in it so he can tire himself out by running around and exploring.

Also make sure to not feed too many hornworms or superworms, these two are treat feeders so its best to possibly feed them either every two days or once a week.
Possibly the hornworms can be fed every other day as they dont have much fat like the superworms but are very very high in water which can cause diarrhea.
The superworms and their very high fat content can cause fatty liver disease if given too much. I'd say for both of these only give 3-4 max.

As for sexing him you can also lay him on a flat surface, arch is tail up a bit and slightly above his vent there should be two bumps indicating hes male, if theres one bump hes a her.

Can you go over his lighting and everything about the lights, brand, type of uvb, everything.
Along with what his temps are and how your monitoring those.

I agree with the advice given above and also thank you for taking him in to give him a happy home! It does just sound like a (possibly seasonal) energy burst so if you can give him a safe place to run around and burn off energy it would be good. If you can set up a portable basking light for him, he will learn to return to it to warm back up as needed. It's possible that he is just a live wire and he finally has enough energy and health to do his thing. That's how my guy is. (He has just completed his - at my rough count - 5th lap between the kitchen and living room so far this morning). If you can post photos of him and his setup, it would be helpful. You can upload photos here https://www.beardeddragon.org/useruploads/ and post them to your thread using the XIMG button. If his weight is up and he looks healthy it might be good to hold back on bugs to try and get him eating more veges. That can take some patience and tough love if he isn't used to veges but shouldn't be done unless he is already at a healthy weight. His activity level tells me it might be time for this.

Hi guys, thanks so much for getting back to me, both of you! I have only just figured out how to post a reply, so I hope I'm doing it right. I'm at work at the moment, so I will have to check on the lights when I get home, I'll also try to post some pics then, too. As they had him with a particular set up for (what I was told was) four years, I didn't want to change things too much at once. The only change I made was to switch him from a red heat lamp to a violet one, as I read that the colour red can hurt their poor little eyes. Other than that, I have slowly added cage furniture including nice flat clean rocks and a jute hammock. Just this past weekend I got him some background scene, you know that plastic two-sided picture roll? I thought maybe it would help him figure out that his tank has walls, and they're not permeable lol. He still continues to try to push through the glass though, and he is super nosy and I don't think he likes not being able to see out of two of his four walls, so thinking I might remove it for him. He is a dear, dear little guy, and I just adore him. Unfortunately I have to leave him in his tank while I'm at work, but am working on a safe place for him to run around like a little maniac after I'm home for the day. Last night, he put himself to bed between my dog's bed and the wall, all tucked in there like a silly little weirdo hehe. Of course, I had to take him out of there and put him back in his tank, but he barely opened an eye while I did that. He is sweet and funny and stubborn and so nosy. Going to do my best for him, and again, thanks so much for the replies and support! It is so appreciated, and just being a part of this little community is making me feel better about everything.
So, will post again later with info on lights, and hopefully be able to upload some pics!