I don't own a Marlin and I seldom shoot lever guns.I might be all wet here.
Sequence of operation:
Lever pulls locking bars down clear of bolt Did we get that far? Probably.
Then the lever starts to pull the bolt to the rear.
There will likely be enough slack between the bolt face,rim,and extractors to permit the bolt to move .020 or .030 to the rear before the extractors on the rim of a stuck case stop the rearward motion of the bolt.
A lever gun have very little primary extraction power,unlike a bolt gun.
A proper hickory wood ramrod is made from a hickory split,meaning the grain integrity is essentially parallel and full length.
A lumberyard dowell has no grain integrity and very little hammer bumping can cause it to fail.When it does,two long tapers wedge the pieces stuck tight in the bore. Desperate moves such as penetrating oil help swell the wood. Better,just don't use a dowel in the bore.
If you have a 3/8 or so brass punch for drifting sights,odds are if you preload the extractors against the rim,and the rifle is vertical,butt on the floor,just dropping the punch down the bore will knock it free.
Next? Get a clean,straight length of 5/16 or 3/8 steel or brass rod and "escalate" a bit.
DO establish that it is not the hammer or other internal parts preventing the bolt from moving to the rear. Beating the bolt to the rear when the hammer/sear are at half cock,for example,would be destructive.
And I suggest you might pull the screws out of the tube mag plug ,pull the spring and follower,and clear out any ammo.
You also might use a cleaning rod to measure the muzzle to breech like an oil dipstick to verify its empty brass in the chamber.