I think my very first gun building project was a CVA pistol. I shot it for years, not a bad lil' gun for the money in those days. Here's something that I learned from it.
The stock on your gun was shaped by a machine. The inlet for the trigger may well have been put in too shallow. My suggestion is that you get in there with a sharp chisel-like device and remove wood to bring your trigger up toward the sear until there is only a tiny bit if wiggle.
Warning! There should be some wiggle for safety reasons. So remove wood slowly, fit the trigger often as you go so you don't take it too far. When you have about 1/32" of play at full cock you are close enough.
I have two of those pistols and both have loose triggers. It doesn't bother or distract me so I've done nothing to fix them. They are both great shooters and that makes me happy and I have no desire to fix the triggers. However, if they drive you crazy I guess you can try and fix them.
Loose triggers are pretty common on a lot of single trigger muzzleloaders.
Like laffindog says (in so many words) better loose than tight.
A tight trigger with no movement at all means the trigger bar is lifting the sear arm which results in the sear not fully engaging the full cock notch.
The trigger is loose on them and if yours has an adjusting screw on the tumbler ( to adjust trigger pull) that can make the trigger even looser.I have the Traditions version, same issue, but when I shoot it, I really don't notice the play.