A couple months ago I put in a fighting conch thinking it would be cool to watch stir around. Well I've seen his whole body 2 or 3 times. Most of the time I get to see a parascope or 2, sometimes his snout.
I've got two. I find that they are quite active when algae is plentiful, but slow down a bit until more grows in. Your tank looks pretty clean, so I'd say the behavior you see is normal. Once algae grows in, preferably something filamentous, the conch will start moving about more. They are very good cleaners, mine clean around 2 - 4 square inches of sand daily.
Just added a Tiger Conch yesterday and he hasn’t gone under the sand bed yet. I was adding a first cleanup crew to the tank. He’s all over the place, putting in work for sure. There is one hermit in the bunch that is putting in ridiculous work as well. I had some brown hair algae looking stuff like 1” long on 4 different Zoa colonies and that one little blue leg hermit had it all completely gone within a couple hours.