@abeNdorg 

I'm thinking the C9s DHCP would need to be utilized if you want to also utilize the guest network. There is not a way to allow specific traffic from the internal LAN.

An alternative setup could be a router and switch with VLANs configured and APs with multi-SSIDs having associated VLAN IDs. That would use different hardware altogether. Here is our SMB forum if you want to explore that: https://community.tp-link.com/en/business

@Tony 

I set the tp-link router as the DHCP server, and deauthorized the Windows server. Guest computers now receive a IP address, however Android complains is able to get to the internet which is true oh, am I testing with Apple and Windows those are also able to receive a DHCP address but unable to get to the internet. If I turn on the option to see the local network, which defeats the whole purpose of guest Network isolated from the real Network, they are then able to get internet access. Other than trying to do a complete factory reset on this router, what else can I try to finally get a guest Network to work?