I've seen it several times, but don't know about the concrete circumstances, that after I saved my last edit and go back to my watchlist, my last edit is shown as not read, i.e. bolded. How can it be, that I haven't read my own edit? Grüße vom Sänger ♫(Reden) 16:50, 2 February 2017 (UTC)
Here's a screenshot of the version history:
I was logged in as Sänger while I made the screenshot.