w5500 static ip changed suddenly

[superbool]

I'm using w5500 with stm32h743 as a modbus slave station (use w5500 as a tcp server).

Most of the time, it work's fine, but some time w5500 tcp packet response wrong ip address.

w5500 as a tcp server , ip is 192.168.3.105. My pc ip is 192.168.3.104. w5500 response packet ip suddenly changed to 192.0.3.105 . At some time it will be 0.168.3.105 or 192.168.0.105 or 192.168.3.0 . here is the error packet in wireshark:

You can see no. 106254 is tcp request form my pc to w5500, and no. 106256 is tcp response，the response data is right ,but the source ip is changed, that makes my app can't receive any data, the trigger tcp retransmission. but w5500 still use wrong ip address . and the connection not colsed.

How it happens, and how to solve it.

Please help me, thank you.