It seems the evil "NPC dialog played in endless loop" is showing its ugly head again.
When one stands near NPCs, we have to listen to them repeating the same line over and over again. It was my main issue in the D:OS series, and from the comments and mods that sprouted out, it seems to be a shared opinion.
Please let's try and find a better alternative to this! And not only increasing the period of the loop.
As said before, a simple trigger that says the line once when the player moves within range of the NPC would be fine, let it repeat that the next time the player passes by.