I finished Fisher IV and i started Fisher V a few minutes ago, and my quests didn't reset. It could be a server error. So, thanks for your comment, I'll keep it in mind for future problems.
It happened to me two days ago. Now im completing the quests again. If it is a bug, fix it as soon as possible as you can because players can earn infinite money by quests. Now i'm arriving to Fisher V Quest to see if it was a bug or it was a mistake from the server.
In Survival, I started Fisher V Quest and then I wrote /quests to see another quests to do and all my quests have been reset. What happened? Is that a bug or I did something wrong?