EXT2700 N300 Chanel / Mbps locked

[EindhovenNL]

I have an issue with my EX2700 N300. Manual set up was done sucsesfuly. Then I added the wifi connection after I set it up and my Chanels and Mbps sections are locked and I can't unlock them. Before adding the wifi connection to the extener I had it sent to chanel 4 and Mbps was set to 300 and saved it, but now I can't change them.  I have reset the extender multile times but still not the results I wanted. 

Can anyone help explain why this is locking on me?

[plemans]

In extender mode, its linked to your router and based off your router. 

If you change it on the router, the extender will change.

In ap mode (the EX2700 doesn't have), it'll be user selectable.