The Allen bolt for the PGO likely has blue loctite. It may help to get the wrench in good deep and square and tap it in the CC direction to free the bond.
When you reinstall it, add a washer to assure that you do not get it in too far to affect the action...
When you say you cleaned it, did you do a thorough strip and deep cleaning? Bronze brush to the bore and chamber?
Have you got it back together?
The above is the video I refer to and refer others to.