Run the below command through SharePoint Management Shell, entering your ControlPoint Web Application URL as the $cpUrl property:
$farm = Get-SPFarm
$cpUrl = <Enter your ControlPoint Web Application URL here
$farm.Properties["ControlPointWebAppURL"] = $cpUrl
$farm.Properties["ControlPointSiteURL"] = $cpUrl
$farm.Update()
This does not require an Application Pool Recycle or an IIS Reset to take effect.