Constantly hiding bristlenose

I have 2 bristlenose in 2 different tanks. One is an albino about 4" tl in my 25 g, and the other is a calico about 3" tl in my 20g. My albino is out and about the tank occasionally during the day. At dinner time he comes out and sits patiently waiting for his food. My calico however is constantly hiding. Never see him during the day, and very rarely after lights out. I put his food in the tank and I never see him come out to get it. However, when I wake up in the morning and take the remnants out, it looks as if he has nibbled on it. I have also noticed the last couple times I was able to get a glimpse of him, that there is a little piece missing from his tail fin. Also his pectoral fins look a little frayed. But I didn't see any blackened edges associated with fin rot. I've had the calico for about 3 months now. The albino did a lot of hiding for the first month or so that I had him, so I expected the calico to do the same. However it's been longer, and it's making me nervous that he's hiding all the time. The calico I did get from a fellow hobbyist and the albino I got from a LFS if that makes any difference.

Water params have all been fine. No ammonia or nitrites, and nitrates are always below 10ppm. Tank is moderately planted with various anubias. His tankmates are 3 male dwarf platies, 6 glow light tetras, 2 endlers, 2 nerite snails, and 1 ghost shrimp.

Should I be concerned or am I just being overly paranoid? It took a lot for me to get this little guy, so I'm afraid to lose him to something I could've fixed.

Best thing to do mate is to get him out and have a good look at him.

Grab a tupperware container and fill it with a bit of water from the tank then catch the little fishy and pop him in the container. that way you can get a good look at him. If you want take a few piccys as well we will be more than willing to help out.

If you suspect there is something wrong then it always pays to check

I have pondered the idea of taking him out and putting him in QT for a little bit. But so far have decided against it for numerous reasons. Biggest one being the stress I would be putting him through just to get him out of the tank. He's hiding in not the most accessible space, and won't budge for anything. I've tried taking a turkey baster and squirting water all around him, hoping to get him to move for a glimpse, and he won't even flinch. Just stays planted at the base of the driftwood "tree".

I came up with a weird idea last night, and covered the tank with a black towel to see if it would help. The tank is situated where it will get indirect lighting from surrounding rooms after lights out. This morning I did notice it seemed he ate more of his zucchini than usual. I'm wondering if it's because he came from hobbyists, and not an LFS where there is a lot of commotion.

After the previous post, I finally was able to get the little guy to budge from his hiding spot. I got a good look at him and his pectoral fins are in good shape and no frays. (it has been awhile since I was able to get a good look at him, so they must have healed in the mean time) However his tail fin still has a little piece missing at the top. So looks promising as far as his fins. I'll keep making sure he's got a good clean environment and keep an eye on them the best I can.