Functioning as designed. When Using ACS the system will automatically assess the best possible channel width for the AP/Deployment configuration. It will assess at 80, then 40, then 20 if necessary. Per the same logic as ExtremeWireless, will assess at the larger widths and reduce until it can resolve a balanced plan for the site, so eventually settling to 20 Mhz if necessary. Since 20 Mhz is always the minimum length it is available to skip the width assessment.