There is a known bug where the character's momentum may carry them outside an NPC trigger box while activating a conversation. This can occur if the character is running and the interaction command is pressed to start a conversation, with the character's trigger box only slightly overlapping the NPCs trigger box. Then the character's momentum carries them slightly outside of the bounds of the conversation trigger box.
This appears to happen very infrequently, but if you run into this issue please pause the game [ESC] and restart the level. Your items should be saved in the games state which acts as a temp save file while the game is active.
Thank you for your patients while I figure out the best way to approach this issue!