@Brianc, it appears that you have crusted fouling between the ball and the breech. Using a solvent on top of the ball may not penetrate to the crusty fouling and soften the blockage enough to move the ball, although
@Britsmoothy's approach can work.
@Idaho Ron, it looks as if it's another call for your excellent video on removing a stuck ball with the use of a grease gun.
Pulling a round ball | Page 2 | The Muzzleloading Forum
There are four tools one should have in their gun kits.
1. A sturdy working rod of brass or stainless steel threaded for the cleaning jags. Particularly one that does not rotate and has a tee handle.
2. A ball pulling tip with a bore sized collar and deep threads.
3. A CO2 ball discharger.
4. A grease gun with the appropriately sized threaded Zerk fitting for your rifle. The grease gun can exert more pressure in the bore than the CO2 discharger.
5. Is optional. The emergency phone number of a muzzle loading gunsmith with the proper tools to remove the breech plug and rod to drive the stuck ball out.