Did i see this same post on reddit or am i dreaming lol?
More to the point, the only legit advice i can give is 'rest after every battle'. It is the only way to unlock all scenes, mind you even then some convos might not trigger right away. With Wyll i had to rest like 3-4 times before his after-Spike dialogue showed up. And that's just one example.
Scenes being hard to trigger or bugged is basically an EA thing, i doubt they're that hard to get by design.
