It drops there, took me close to 30 tries. It's part of the known issues with 2.45:
2.45 Patch Notes
In the sidequest “A Ponze of Flesh” the map does not appear when clicking on the objective “Obtain a gobmachine bangplate from Brayflox’s Longstop (Hard).”
They might have fixed this issue, but along with it was the no red circle on last boss.