How to sync folders on LAN when router has AP Isolation / Client Separation enabled?

I’m using Syncthing to sync folders between multiple devices on the same local network (PCs, laptops, etc.), but I’m running into an issue caused by the router’s AP Isolation / Client Separation feature. Connections via Relay WAN are too slow.

I’d appreciate any advice, best practices, or real-world setups that work under these constraints. Thanks a lot!

Is it possible to setup an explicit route between the two machines on the router? (Do they have static IPs?)

do you have administration control over the router?

I’m presuming there’s a good reason in your specific instance for the isolation to be enabled?

Definitely, I don’t have the privilege. The device belongs to company. Btw, maybe there is a few Syncthing-users in China, and isolation is reasonal for security.

If you don’t have access to the router settings and the two devices cannot connect directly then I don’t know what options you have aside from a relay on another network.

Maybe someone else has direct experience here.