I know nothing of the newer/recent mfg'r 357 & 44mag Model '94 Marlins, but just going on what I do know of the earlier 1894's,, cartridge OAL is critical.
That was true even for the 1894 44mag reintroduced in the late 60's.

Too long, and the bullet nose can still be partially inside the tube as the carrier is trying to be lifted up by the lever motion.
That jams the action , but quickly clears as the cartridge falls from the carrier and rifle if it is rolled to the side or upside down w/ a bit of tension removed via the lever.

Too short,,allows a second cartridge to partially jump onto the carrier along with the one that's supposed to be there.
It jams the action in the same way but is much more difficult to clear as neither wants to nicely fall and roll out of the receiver.

The problem, if it is one, is that there was (is?) no separate cartridge stop in the Marlin. The carrier is the cartridge stop itself (at least in the older mfg rifles) and the OAL of the round is very important.
The mag spring supplys the spring tension against the front face of the carrier in it's travel. Either the base of the next round in the mag or the follower in an empty rifle pushing on the front end of the carrier.


Try some ammo with a slightly shorter OAl as suggected before anything else.

The bullet shape can effect feeding out of the mag as well as into the chamber too.
Use very blunt round nose or flat nose bullets both for safety and feeding in a lever tube feed.