I have been wrong before, but that looks like a magazine issue to me. Does it behave that way with different magazines or always with that one?
(Top pic. Bottom pic, not so much.)
Agreed! Only 1911 mags I run are the Wilson Combat 8 rounders and the Chip McCormic Power Mag 8 rounders. IMO, most factory supplied 1911 mags are pretty crappy. A great 1911 mag sometimes makes all the difference in the world.