According to the latest firmware version of the firmware download center, which it is v4.7.11, v4.7.13 has not been officially released yet, please wait.
We also reproduced this problem on Flint3.
The issue is caused by the Luci firewall accelerate rules flow_offloading '1' and flow_offloading_hw '1'.
The accelerate of Flint3 and Slate 7 use qca-nss-ecm module, which is not adapted with the Luci. After configuring it in Luci, and the /etc/init.d/firewall restart will report the errors, or aftet restarting the router, the firewall LAN rule is lost (br-lan traffic does not allow access to the router local service), resulting in all services are unable to access, like DHCP, SSH and Web UI, etc.
Please configure "disable/enable" the network accelerate feature in the GL GUI.