I've yet to read or hear anyone come across this glitch yet and doubt many people will encounter it. But some will just as I did. If you do, don't panic. Simple solution.

The glitch is for the Challenge Accepted trophy. I'll tell you how I encountered it. 1st, Jimmy Jenkins is a real pain in the ass and I blame him for this. I found it extremely difficult to get the little metal bastard to appear. 1 of the most frustrating things in Borderlands 2 by far in my opinion. Pure luck and me don't get on unfortunately. So after completing every level 1 challenge, I obviously focused on Jimmy. I found it tough getting him to appear, like I said. I tried everything. It was agonising. So I read that it's easy to get him to appear in 1 of the 4 boxes in the wildlife preservation area. The boxes are the 4 cardboard boxes in the room to the right of the place were bloodwing was supposed to have been being kept. Those who have played the story will know. I won't spoil anything for those who haven't gotten there yet. But anyways, there are 4 boxes he can spawn in. 1 has a recorder module (think that's the same) in it for a mission that Tannis wants you to do called Doctors Order. Credit for this method goes to cocoasg who posted the method Here.

My issue was that I had done this mission on both Normal and True Vault Hunter Mode so I was in a bt of trouble. So I came up with the idea to choose another existing character and get them up to that mission quickly then use the multiplayer option with 2 controllers to farm Jimmy Jenkins. It took forever and I finally got him after getting every other enemy maybe 20 times each. I used my level 50 character to run through the area on Normal and just keep trying. When I got him, the challenge was complete, but no trophy. I checked an online guide and I saw that all challenges and hidden challenges were level 2 and above. So I was in a bit of a worry. Naturally.

Let me get to the real point. My title is a little misleading. This is not technically a glitch. Both saved classes/characters were my Glasgow_Mick89's. The issue was that my 2nd controller is the level 50 character who killed Jimmy and did all the challenges. It cancels out the trophy because completed trophies are focused on the 1st controllers completions as legitimate trophies. Most people will already know this. Some wont think about it... Like I did. Or didn't.

With the solution though this isn't a problem. So it was actually a win win for me. All you have to do is go back to playing single player and load up your 50 character (the 1 your doing the challenges for), find a challenge that is almost completed to the next level and complete it. Then pop.

A lot of people won't use my method for Jimmy Jenkins and come across this problem. But some may. And then they might be in a bit of a rager and unsure of what to do next. Just do as I said and you'll have absolutely no problems.

Hope this might help the minority, like myself, who come across the same problem.

Who really likes to do things the easy way anyways? Like I had a choice.