Please read the posts after @Lewk's reply as there is information on how to check if this is a conflict with 5 GHz radar bands.

c0ld:

 

This is the way I've done it, may be another. 

 

Firstly, you can view 5Ghz channels to avoid using the table found under 5 GHz or 5.8 GHz (802.11a/h/j/n/ac/ax) subheading:  https://en.wikipedia.org/wiki/List_of_WLAN_channels#5_GHz_or_5.8_GHz_(802.11a/h/j/n/ac/ax) - avoid the ones listed under NZ that mention DFS.

 

Now navigate to Wireless > Radio Channel and click Refresh (i'm viewing on a mobile browser, its next to the apply and cancel buttons at the bottom but may be different on PC browser). Under Use of Wireless LAN Channels make a note of a channel (2.4Ghz first) that is showing low occupancy. Now click the 5Ghz tab and do the same, avoiding the DFS bands noted in the Wiki article linked above.

 

Now change Radio Channel Settings from auto to Adjust radio settings, choosing your new selected bands (as an FYI I have channel 40 for 5Ghz and it works a treat, no DFS issues). Under additional settings I have (not sure what was default) 2.4 standard set as n+g+b, 5 as n+ac, 100% tx power and have ticked devices can auto move between 2.4 and 5 when required as long as same SSIDs.

 

 

 

Hope it sorts it for you.

 

 

 

EDIT: And just to mention, if the performance of the channel isn't great you can of course try a different one until you find whatever works best whilst still avoiding the 5Ghz DFS ones.

 

Thanks!!

Have just changed mine and will monitor it as you have advised.

Hi All

This has been now raised to AVM and awaiting a response. It is not a fault Fritz!box kinda works 100% to the standard. ( 802.11ac ) 

For the time being please swap the Wifi Channel on 5GHz to a UNII 3 band - Channels 149 - 161

For the 2.4Ghz - if you purchased your devices in NZ ( Not parallel imported ) then tick turn on the channel 12/13.

regards

Z