I was recently making a map where I wanted to make a conversation trigger when an amp gem was collected. The amp gem has a selection menu to allow conversation but every time I selected the conversation I wanted, pressed apply and then un-selected the gem it reverted to NONE. I ended up putting an info cache under it to trigger the conversation and working the dialog a little to make it fit the story. But it would be nice to know how to fix this problem.
Conversations do not stick to amp gems. I've reported the bug already. It could possibly be PRPLed.
PRPL-wise, suitable code can be found on story mission 6.
You may also check attached test mission with a script as temporary workaround. Inputs are better described in comments inside the script.
I'm fixing this right now and it will go out in a new public 1.1 beta later today. This has slipped by too many times, so hopefully it will be ended today.