Slate 7 (GL-BE3600) VPN issues

Currently seeing unexpected behavior when running wireguard client on the router and the routing policy is set to VPN Policy Based on the Client Device. I have it configured to only route through the VPN for specific clients.

With this setting I'm expecting that requests from the router itself by default wont go through the VPN. But if I ssh to the router and run curl ifconfig.me The IP I get back is the IP of the VPN instead of the local IP I'm connecting from.

The device that's configured to go through the VPN is going correctly through the VPN. Clients that are not set to go through the VPN are also correctly not going through the VPN. The issue seems limited to requests originating from the router itself that appear to be sent via the VPN even though is not supposed to. Noticed this behavior both on 4.7.1 and 4.7.2 version of the firmware

You are correct.
On the existing firmware, the router's own traffic uses the VPN by default.
We are also aware of this issue internally.
In the new v4.8 version, as you suggested, the machine's own communication is carried out by default using the uplink interface provided by the ISP.