Cambium E400 40MHz Channel issues

Is anyone else having issues with the 40MHz channels on the 2.4GHz band on the E400?

I manually set the channel in the configuration to channel 11, save the setting and reboot. Then using INSSIDER i can see it come up with the 40MHz channel but then it disappears and drops back to 20MHz. The local login to the device shows its still 40MHz on the dashboard.

I can get it to work on Channel 1 to channel 8, but anything over that and it wont stay on 40MHz. I really want to use channel 11 as that will make it so its not overlapping with my other AP on channel 1+5.

I have engaged in a support ticket but the level 1 tech support seem to be out of there depth

Sorry for the tag :)

@mcraenz @hio77 @rwittert @miked @michaelmurfy @RmACK @Earbanean