OK,I looked at the pic.Note your dud is a light,off center strike,and your fired round is a strong center strike.
That indicates to me your pistol is semi-locked up as you are trying to fire.
As I described,I messed up a good 1911 that way.Do not keep doing that!
Check your locking surfaces for battering.
For a while,till this is resolved,make sure your slide is 100% fully fwd before you squeeze!
I suspect scraping bullet metal on the case mouth or not understanding crimping.
I suggest you add a Lee factory crimp die to the 4th station of your press.
Then just leave the RCBS seater set up backed off from the shell holder,to just seat,and crimp in the 4th die