capsman wireless configuration

RouterOS Wireless Networking
1

Hi,

I'm trying to set up capsman with a configuration like this:
[admin@MikroTik] /caps-man> configuration print
0 name="cfg1" mode=ap ssid="micasa" country=germany distance=indoors security.authentication-types=wpa2-psk
security.encryption=aes-ccm security.passphrase="*******" datapath.bridge=bridge-local
channel.control-channel-width=40mhz-turbo channel.band=2ghz-onlyn channel.extension-channel=Ce
rates.vht-basic-mcs=""

but it fails:
[admin@MikroTik] /caps-man> interface print
Flags: M - master, D - dynamic, B - bound, X - disabled, I - inactive, R - running

NAME RADIO-MAC MASTER-INTERFACE

0 M BI ;;; no supported channel
cap1 4C:5E:0C:06:EA:4F none

Somebody has a hint why this is an unsupported combination? I intentionally left the frequency blank for autodetection of less crowded channels from the different caps. (Currently there is only one connected.)

2

Try change channel.control-channel-width=40mhz-turbo to 20Mhz

3

20MHz works but I’m a bit puzzled. When I set it to 20MHz and use my frequency scanner I still see the wifi network spanning 8 channels instead of what I would expect 4?
So is only the extension-channel=Ce relevant for the behaviour and what does the 20MHz mean then? Is it 20MHz just for one channel/frequency while extension-channel enables a second one with 20MHz again?