Problem trying to send traffic to same node different ports using two different VS and pools

Hello, the following is our setup:

mypublic_URL:443 -> VS1-192.168.1.100 URLrewrittenTo_myPrivateURL-> pool:443 -> webserver1-172.28.1.100:443 mypublic_URL:4443 -> VS2-192.168.1.101 URLrewrittenTo_myPrivateURL-> pool:4443 -> webserver1-172.28.1.100:4443

We have two virtual servers with the same IP, but different service ports rewriting a public URL to a private one, pointed to two different pools with different service ports on the same host as diagrammed above.

We don't have any irules configured for this. The problem we're having is that requests for mypublic_URL:443 are getting responses from the webserver1-172.28.1.100:4443 site instead of the 443 site. My research thus far would indicate that using two different pools should allow using two different service ports on the same node/host. Is there something I'm missing here? Thank you,

Ben