HELP! why my ros uptime becomes zero

Last night,zabbix alert system send a sms and tell me my ros uptime from 497 days becomes zero days,I log in immediately,but do not find anything in logs,In other words, I can not confirm that the system has been restarted。Can everyone provide some advice,Thank you。

If I remember well it was a counter reset bug with old versions. What version do you use?

Thank you for fast reply。I use CCR1009-8G-1S-1S+ version:6.33.1 (stable)