EX6200, change Net Channel Wifi 2.4

[Clivio]

Hi,

I do an update of the EX 6200 firmware. Now I can't change the net channel wifi of 2.4Ghz, the choise is gray and write on "Automatic".

I use the EX 6200 like an Access Point, my "internet" come from ethernet.

This changed with the new firmware is a problem, because all EX6200 go in channel 1 to 3.

So, how i can change the Channel?

Thanks

Clivio

[plemans]

If theres an issue after updating firmware, a decent step is to factory reset the extender and reinstall it. 
Have you tried this? 

We usually run into the channel's being locked when its setup in extender mode and not access point mode because extender mode runs of what channels the router is using.