As mentioned above, we configured a schedule weekly reboot, IP address was issued to clients within DHCP scope, but clients cannot access internet after the reboot intermittently, usually I need to manual reboot again then it can work, can anyone teach me how to resolve it permanently? thanks.

After the automatically reboots, are you getting the IP from the DHCP?
This is a not normal issue, we need to know first what is happening and at 99% the, the problem is not in the mikrotik...

After those automatically reboots, clients are able to getting IP from DHCP.
When the problem happens, usually a manual reboot on Mikrotik can resolve it, so I'm pretty sure this problem is in Mikrotik. But all log is emptied after reboot, so any suggestion how to do troubleshooting?

I am asking about getting IP in the Router from the Bridge/modem, if your MK is getting the IP, not your clients

MK are not configured to get IP from DHCP, we're using MK to provide service of Captive Portal.
A particular VLAN is configured in the main route and MK is a member of that VLAN to access internet.

When the problem happened, usually a manual reboot can resolve it.