You discover that some clients do not use all channels in the 5 GHz UNII-2...

In a Juniper Mist environment, the Radio Resource Management (RRM) system is responsible for the automated allocation of channels and transmit power across all Access Points (APs) at a site. When you modify an RF Template—for example, by excluding specific UNII-2 Extended channels that certain legacy or region-specific clients cannot "see" or support—you are updating the intended policy for the network. However, because Mist RRM is designed for stability, it does not always force an immediate, disruptive channel change across the entire site the moment a template is saved.

To force the Mist AI engine to immediately recalculate the channel plan based on your new constraints and push those settings to the APs, you use the Optimize Now button. This feature is found within the Radio Management section of the site settings or the RF template application page. When "Optimize Now" is triggered, the Mist Cloud analyzes the current RF environment, takes your new channel exclusions into account, and issues a command to the APs to switch to the most efficient channels available within the newly defined subset.

Choosing Restart the APs (C) or Restart the WLANs (B) is unnecessary and causes more downtime than required. A reboot might eventually result in a new channel selection, but it does not guarantee that the RRM algorithm has fully processed the global optimization for the site. Restarting clients (D) does nothing to change the AP's channel behavior. By using Optimize Now (A), you ensure a coordinated, AI-driven transition that minimizes "co-channel interference" while respecting the updated frequency constraints you defined to accommodate your specific client devices. This ensures that clients previously struggling with unsupported UNII-2 channels are immediately moved to compatible frequencies.