I have several HS220 smart switches installed that randomly behave in a similar manner.  The switch will receive an OFF or ON command, the LED indicator on the switch face will change state, but the lights will not follow suit.  If I press one of the dimmer buttons on the switch face, the lights will change to the desired state (on or off).  This has happened when pressing the paddle on the switch, or remotely over WIFI.  For instance, my Home Assistant installation will issue an OFF command to a light switch, the LED will turn on, suggesting the lights have been turned off.  However, the bulbs remain lit at their previous level of brightness.  The switch will report back to Home Assistant that the lights are off.  The switch/lights will remain in this state until I intervene.  The appears to happon randomly. 

Has anyone experienced this behaviour?  Is this a known issue, and if so, is there a fix?