I bought a set of 3 Luma surround wifi (https://www.amazon.com/Luma-Whole-Ho...&keywords=luma) from Amazon US.

Unfortunately, while configuring the same with my ISP (tried Airtel and now Metronet), realised it doesnt work with PPPoE. I tried using my old TPLink wifi router and connecting the Luma router to this but that too failed.

Is there something I can ask my ISP to allow this router to work or I need to ship it back?