I am on 2.0.60. I don't tend to play the experimental version.
I did some investigation myself. It might be related to the train screensaver mod. It tends to happen fairly regularly when I leave and come back to that screensaver thing. I will disable that mod for the time being since it is aesthetic only. Perhaps that mod is creating a player entity or something and triggering it.
Do you have any preferences for where to put the save file?
Edit: This is the train screensaver mod I was referring to https://mods.factorio.com/mod/trainsaver
Perhaps when I exit out of that it is counting as ending the curscene.
Edit2. Yes. Whenever I manually trigger the train screensaver with that mod, it creates new starting equipment.