session time problem, help newbie please

first sory if my englih speaking not good,
i have problem with session time..
if i reboot mikrotik, session time for trial user and user from usermanager ALWAYS reset session time.

example :
T-50:D5:48:00:56:F4
limit uptime 01:00:00 and allready use uptime 00:30:00
if i reboot mikrotik ..
T-50:D5:48:00:56:F4 limit time back to 01:00:00 againt

what’s wrong in my setup im confused really really confused help me guys please