This means you setup as noted and did not use it's WAN port.

I am running into folk that did not actually set up the router as a WAP and thus ran into your issue.

Here's the google that I use to refresh my memory on how to setup a router as an access point.
https://www.google.com/search?q=How+to+use+a+router+as+a+WAP

Also worth mentioning is once in a while someone drags out an old DSL modem to try this trick on. For me I call that unsupportable and may not help.