The pin is in properly and it is on the rails properly.
It is just a slight loseness at the end of the gun. It wont move if you try to wiggle it in the middle or back, where the frame rails are. I am not really that worried about it. Just curious if this is common with these guns.
Mine has always had a little wiggle, when locked and loaded but nothing that would affect the shooting. I worried about everything, including the barrel seeming to be loose in the slide. I originally thought that guns should not have a barrel that tipped up when the slide was locked back. I have learned a lot in the last year, from the guys here.
My PT111 Pro has about 3000 rounds through it with just a little wiggle to it but its been that way since new and has not gotten any worse with all the rounds through it so I guess it just depends on how it fit at the factory