So, I've noticed this happen a few times. The plane will change the nav src at the inappropriate time. I'd say 3 out of 5 of my last flights. I had a hotkey setup on my hotas for nav src toggle button, and de-hotkeyed it to make sure it wasn't a "noisy" button signal, as this does happen sometimes.
During this flight in particular, there was no hotkey for this, which verified to me it seems to be the plane itself.
I've also included what I believe should be the correct log as this was the last flight I did.
Time stamp: 4min 50sec. Sorry, I didn't take the time to edit the video.
Log.txt