There are several NPCs who are known for glitching. For example, yesterday I walked to a NPC for continuing a quest and started a conversation. After the first option to select, I was able to read the answer for one second, then the conversation closed and since then I can't start it anymore.
When I move away from him and approach again, he does his voice-acting like "hey I know you, talk to me", but it is not possible to start a conversation. Some other PCs standing around stated in the chat that this poor boy is known for glitching.
How can I fix those glitched NPCs or are there ways to avoid glitching in first place?
Some mates say it's possible to completely close the game and then login again to start in another instance on the server. Others say it can take up to 30 minutes that an instance gets resetted.
Is there no other option to just wait or do other things?