I can't seem to enthrall the moth priest or enthrall the poeple for the side quest. I have tried restarting from a save before i got the quest and that did not work. so does anyone have any idea on how to solve this?

You got the problem that clicking enthrall after seduced but it do nothing right.

I got this problem too and end up using console to skip the quest.

Wich code did you use to skip the quest ? I've got the same problem ...

Vampire seduction + feed. If you're not getting him "under your spell", likely you're "missing". Go into first person mode and try it.

For some reason, 3P perspective is a bit off with DG and it seems mostly to lean right (i.e. you're aiming more left than where you think you are. This seems only to be non-combat, and I'm speaking to PC platform only.

That's not it. The target is hit and glows greenish blue but there is no option to feed. In my case, I was able to enthrall the moth priest normally but later on in the side quest to recruit a new vampire, the vampire seduction power does not lead to a seduced person. Pickpocket is the only option and talking to them elicits a response but no interactive dialogue. I can feed normally on a sleeping person but not a seduced person.

Have you had vampirism before and bene cured?

No. First time vampire.
And like I said, everything worked as it should on the moth priest but on the Cairine target in Markarth given for the "New Allegiances" radiant quest, I can't get her to submit to my embrace.

After searching on this topic a bit more, it seems like this is a common glitch. No solution yet.

Hrm. No issues with it here...

Another possibility, you're only supposed to do this when/if "nobody" is around. I've found that this is not entirely necessary and may be dependent on your sneak and/or pickpocket skill. For instance, my thief has no problem doing this in broad daylight, out in the open. Which makes me maybe think it's tied to this OR maybe something even as weird as having tried to pickpocket an NPC and failed. Like when you don't even get the OPTION to pickpocket. Just throwing that out there if any devs are "eavesdropping".

setstage DLC1VQ03Vampire 70

http://www.uesp.net/wiki/Skyrim:Prophet_%28Vampire%29

scroll to bottom of the page you can see how it work

I thought of that and tried killing the only other NPC that was in the Warrens in Markarth before trying the seduction. No dice. And the other NPC is too high of a level to be seduced himself.