Unable to connect to Deck when connect from a device in the real sub-net

[TigerBeanst]

First, I run Tailscale on my Router(192.168.31.2/100.64.0.2).

tailscale up --reset --login-server https://xxx.xxx --hostname my-router--accept-routes --advertise-routes 192.168.31.0/24,192.168.101.0/24,192.168.1.0/24 --accept-dns=false

Then, I use a computer(192.168.31.7, which gateway is 192.168.31.2) to connect my Steam Deck with 192.168.31.137(which gateway is 192.168.31.1), it failed. But if I use 100.64.0.3, which is the device ip in Tailscale, it works....

If I just down my tailscale on Steam Deck, connect to 192.168.31.137 works again