A week ago, I traded into yet another LNIB Sport II (I loves me some wheelin'-n-dealin' on the Armslist! ), and took it right out to my secret range nearby for a quick test fire. In the first couple rounds I had the exact same issue the OP had: a round jammed in tight, and wouldn't seat or extract. I finally pulled it loose (just tugging on the charging handle).
The round was bent and looked just like the one in the OP's pic.
I had a feeling my magazine wasn't fully inserted (I didn't think to check before removing it to deal with the jam).
After that, the rifle ran flawlessly, and did so for the next 3 consecutive days.
The last day I was out there (day before yesterday),while using my motorcycle seat as a rest, the seat rubbed against the magazine and pulled it out a little. I gave it a slap, and checked it, and it still didn't seat, so I popped it good, and it locked in. This was a P-mag, same as I used when I had the glitch, so I'm pretty sure it was just an improperly seated mag, and wouldn't be surprised of that's what happened to the OP, as well.