Try opening cylinder and while its open, depress the cylinder thumb release back and forth to see if it moves easily.
If it does move freely, then check (by hand no tools) that your extractor / ejection rod is fully screwed into the cylinder end.
Last you may want to check the gap between the cylinder front face and the barrel forcing cone for contact while cylinder is closed, check each chamber while slowly rotating cylinder.
Depending on your skills and familiarity, these would be the obvious points of a problem.
Seems like you have some experience with revolvers as indicated by your last post.
I on the other hand,am slow posting and struggle with keyboards and teeny tiny letters on the screen and usually complete my suggestions long after an OP has posted.
So disregard