Hello Greg - A few thoughts come to mind. 1. Have you checked your AP settings since joining it to the controller? Is it possible the controller has kicked the AP back to a 20MHz bandwidth? 2. What about channel selection - is the AP at 40MHz using the same two bonded channels? If not, is it possible the "other" channel being bonded is in the same range as an interferer in your environment? 3. Is the image downloaded from the controller the latest version?