I have a non TP link modem, and i purchased 3 TP link AC 750extenders , when trying to set up a mesh using the target app it keep creating each extender as a separated network however the main reason I purchased this item is because it was advertised as one WiFi name, can someone direct me on how to create this?

and also how far can I place the extender from the router? and does every extender have to be at that distance from the router?

for example let's say that the extender can be placed 50 ft from the router, can I place an extender let's say 35ft from the router and a second extender 35 ft from

the middle point extender but 70ft from

the router since I'm creating a mesh?