TV OSD popping up when new video starts from playlist?

Hi, I’m running Kodi on a Pi 3 connected to a Sony Android TV and so far I love it. I’m having a problem, though, playing a folder full of short videos by selecting the video directory from the context menu. The problem I’m having is that at the start of every video, the *TV’s* OSD pops up for five seconds or so as if I’d changed to a new source.

Nothing else is happening, the OSD is just popping up every time a new video starts. This seems like it’s to do with CEC maybe? Is there anything I can do to stop it happening? A lot of these videos are only 10 seconds or so long and it’s really intrusive.