Put them near the same type of element - so a fire dragon with a fire wyvern or rock drake. But do make sure it's one of ours, another mod or base wyverns won't work.

If they're not updating their counter, try going out of draw distance and coming back, sometimes Ark doesn't update properly.

Thank you, I will try that

Okay so I have a Poison Hatchling standing next to a Thorn Drake. How do I know if it is working, the Affinity is at 0% still?

The affinity should go up gradually, but you might have to leave and come back for it to update.