ESP IDF sdkconfig.defaults not applying for ESP32-C6 DevKitC1

I have a project building an ESP32C6 that uses Wifi and ieee802154 but not Bluetooth, so I would like to disable it.

In my current sdkconfig.defaults I have set:

CONFIG_SOC_BT_SUPPORTED=n

However when the board builds I check out the sdkconfig.DevKitC-1 and in there it’s set to

CONFIG_SOC_BT_SUPPORTED=y

Tried adding:
list(APPEND SDKCONFIG_DEFAULTS “sdkconfig.defaults”)

to the CMakeLists.txt at the root of the project but that doesn’t work.

The reason for trying to disable Bluetooth is when I do a WiFi scan I get the error:
wifi:Error! Should use default active scan time parameter for WiFi scan when Bluetooth is enabled!!!

So I thought I would try disabling Bluetooth as it is not used at all.

Any suggestions as to what I am doing wrong?