[Jack]

Not a clue, GOB.
I suppose I would check to make sure I was using the correct die, correct shellholder (some old shellholders were shorter than current ones), and correct brass. Might take the decapping rod out of that sizing die and take a good look inside.
I am not familiar with the case lube you are using. Some of the spray lubes instruct you to squirt some inside the sizing die before you size the first case (also sprayed). Folks forget the squirt into the die part and run into trouble.
That you has similar problems with another die is very puzzling.
Try another lube, maybe?
I like the spray lubes as well as Imperial Sizing Die Wax. Some folks use STP on a lube pad, or pure lanolin rubbed on with your finger.
Check the brass for anything inside it, too.
If everything checks out, I think I would take the decapping stem out of the sizing die, lube a case up good, including the inside of the neck, and try again, without forcing anything.