Changing the channel and Reset are two different things, and we need to improve that page to clarify.
To change the channel, select the new channel from the pulldown menu. Then click on Update (upper right). Then, reboot your hub. The new channel will then appear on the Zigbee info page.
If you have devices already connected in your zigbee network, it may take them as long as 30 minutes to discover their new channel, but they almost always do.
DO NOT USE RESET. This will basically wipe out your zigbee network and you’d have to start from scratch.