Guild Wars 2

Tyria Mastery does NOT work IF the account has already achieved 100% mapping of the original game. Even completing a region map with a new character does NOT provide “experience” to the mastery tracks to advance the account-based mastery.

Your problem and my problem pretty sure same. Here my forum link about mastery tyria bug
https://forum-en.gw2archive.eu/forum/support/bugs/Mastery-Tyria-Bug

I hope ANET, can solve this bug