Certainly it’s not the w5500’s fault
I hooked up the original seeed ethernet card which uses the w5100 chip and the corresponding bagels server and i get the same result. It works fine direct connected but not via the comcast router. I think it might be something to do with using a static IP(which the comcast router seems to want to know about), or the fact that the comcast internal network is 10.0.0.x rather than the 192.168.1.x that i’m used to. The phenomenon is that the olduino sees and deals with the http transaction and sends back its response but it is several seconds before the browser responds to it. It could also be some defect in my code which has been there forever and somehow gets by in other environments. maybe my next step is to put the original w5100 shield on an arduino and try that.