This happened to me as well.
-XboxONE
- Single and Multiplayer
- After collecting the missions "place a field marker at spade gulch" and "place a field marker at the oak tree lab" we played for a bout an hr then my party disbanded and I went to go see Burg L and he was gone. restarted a bunch, and he is still gone to this day. Sucks because I played a bunch after and restarting will not be enjoyable. Also I bunch of ppl saying this on reddit as well. hopeful this gets fixed soon.