What device are you running this on? The W5500 has an actual reset pin that could be toggled so that could help?
Running out of sockets on the device site, is mostly caused by missing
.end()or not handling all calls.
Give curl a try to see the difference.
curl -V <web-server-ip>/index.njs
Feel free to share your code to reproduce it, got some Wiz5500 on my desk.
Yes, the reset pin can help this issue. Or restart the power of the device can also reset the W5500. But this issue will happen in a few minute again.
I used wiznet 5500 for tcp connection, but sometime I didn't know why it stopped. And then I tried to reset system, but the socket not avaiable still exiested. I had to power off the board then the wiznet work fined agnin.
How to reset WIZnet 5500 while socket is not available?
No free sockets found
This is my code, and run on the board STM32F4DISCOVERY