I was doing the following three quest in Badlands:
And then I noticed DBM's feature of not showing a cinematic you have already seen prevented the second and third quests from being functional.
When you are on those quests, your character gets replaced by a playable cinematic character, and you perform the actions described in the quests' stories.
Once completing the first quest in the chain, DBM learns which movie it is, and thus never lets it be seen again. If you fail the first quest, or move onto the second or third quests, DBM automatically exits the cinematic and you cannot do the quests.
When I checked the saved variables for DBM, I saw a list of "MoviesSeen", but that doesn't help me because there is no description to indicate which movieID is which.
What I suggest to fix this is perform a zone check before exiting a cinematic. Assuming Blizzard adds more such quests, then exit the function that cancels movies if you are in x, y, or z zones. Badlands is zoneID 3.
Things might get complex if the player has the map open, but it can be done.