@Axelus 

Well, I don't think it will affect any other equipment in the network if we cannot access tplinkeap.net, which is only a domain name for login the web UI of a standalone Omada EAP.

As an access point, it's not necessary to log into the EAP's management page to configure it before we get the Internet access from the EAP's WiFi. We just need to hook up the EAP225 with a router via Ethernet cable, ensure the router is working then the EAP's WiFi would provide a working wifi for the wireless clients like cellphones. And that's the basic point before we can access tplinkeap.net. So you may confirm that whether you still have Internet access from the EAP when you failed to access tplinkeap.net.

Read this guide if you failed to log into the EAP via tplinkeap.net. Hope that helps.