CEC keeps switching TV Input back to Kodi

TV Sharp Aquos LC-70C6600U
RP2 Kodi: 6.0.3
Kodi CEC setting are currently set to the defaults

CEC seems to work fine, but if the TV input is switched to another HDMI port the input will auto-switch back to Kodi within a minute or two without touching the TV remote. I’ve played with the Kodi CEC settings, but have not seen anything that makes a difference.

Any ideas?