Maybe you should try downloading it. That fixes about anything. But the age is still at zero?!?! That is pretty freaky. If it doesn't work yo may have to reset it completely, but I highly DON'T recommend that! I have a v6 that will not go to sleep, and nothing will fix it! I just have to pause it at night...
I wouldnt worry about it. Sometimes tamas change at weird ages. I dont think its a glitch though. It just happens randomly. Once my angelgotchi was a toddler until she was 7!!!!! but its never happened since then.
Im having the same problem right now, but I didnt know it counts as paused when you go on tama town *makes mental note to use other codes to play there*
*sigh* now ill have to wait till tomorrow where I have to make it sleep half the day anyway because Im at work 1:30-10:30