Certain things cause my combat form (Celestial Tiger) to stop regenerating Jin. When I chunk, when I feign death, and when I tab out of the game to search the web, my Jin starts to drop. The icon for the combat form stays up, but it is just not functioning properly. In general, if I don't do any of the above mentioned things, my jin regenerates as it supposed to, though I think there are a few other circumstances that I haven't identified yet.