Just upgraded my shield to the latest release, Android 11. Upon doing so, the SDDP connection said "online" but nothing was responsive. After trials and tribulations, the fix was to disable the ethernet connection on the shield (through the menu) and then simply re-enabling cured the problem.
Additionally, when running Kodi now, I was getting a pop-up about a "new controller detected" upon pressing any button on the c4 remote. The fix for this is to use your phone app or native shield remote, go into the kodi settings-->add-ons-->peripheral libraries-->joystick support-->disable. Click ok/apply. Force close kodi and re-open it, problem should be fixed as well.