I went back into Act 1 to try and see if I could get my “Now I Gotta Get Up Again” and “A Mouthful Of Boom” achievements because they among others did not unlock for me when I played before.
So I am helping Lizzie and I figure I might as well try and pick up the heavy weapons again since that was stuck at 80% for me. I grabbed the Buzzkill using Jack, and sure enough, POP! (NOTE: I know I picked this up previously because I did it before in the mine/phosphorus side mission after fighting the Swarm on the ice lake and one of the Scions had it). Note: you can find enough components in the Act itself before this point to give Jack this ability if he does not have it already.
So I get to Clayton, and “Now I Gotta Get Up Again” popped. So I am moving to see if I can get “A Mouthful Of Boom” and the campaign completion done by playing the last checkpoint (or Act completely) again. Wish me luck.
Pros - they are unlocking now. Cons - you have to do it all over again?
I did look to see if this was posted, and I did not see a topic like this, so I am making it now.