This is not a superstition for 2.4GHz. Other devices sharing 2.4ghz tend to malfunction when 40MHz channels are in use. This is a well known phenomenon. I have been able to reproduce it in my household by enabling 40MHz channel support for 2.4GHz on my ruckus APs while listening to audio from a Bluetooth speaker. The Bluetooth speaker will start having discontinuities in the audio stream that disappear when 40MHz support in the APs is disabled.
This is not a superstition for 2.4GHz. Other devices sharing 2.4ghz tend to malfunction when 40MHz channels are in use. This is a well known phenomenon. I have been able to reproduce it in my household by enabling 40MHz channel support for 2.4GHz on my ruckus APs while listening to audio from a Bluetooth speaker. The Bluetooth speaker will start having discontinuities in the audio stream that disappear when 40MHz support in the APs is disabled.