I use 'set interface wireless wlan0 channel <channel name>' command to set the channel for AP. But after setting channel for the first time, when i tried to change the channel to different one , using same command , I found AP do not seem to take effect.
I can confirm that new channel number is getting updated in the /var/run/hostapd/wlan0.cfg file, but AP do not switch to the new channel.
If I manually restart hostapd service using 'hostapd-init restart wlan0' my AP do work with the latest channel.