Changing periapsis without RCS
This all of a sudden started happening since Nov. 2017 after playing over 1000 hours on my Steam version in Windows 7 64-bit. I can't get the game to work like it used to before and it makes mission planning impossible.
After an encounter is set up with another body, any movement of the craft causes the periapsis to shift. I was used to this with RCS on, but it started happening all the time. In the linked video with a Duna encounter, you see first that I move the ship without RCS and the periapsis fluctuates. Secondly, you'll notice that if warp is engaged during this fluctuation, it'll throw the intercept way off course. This happens while in Kerbin SOI or the Sun's SOI.
Again, this never happened after many hours of game play until randomly in 2017. I've tried messing with all kinds of settings. Even formatting my computer and trying on a clean install with no mods. Any idea? I would love to play again, but this makes the game too unpredictable.
Thank you so much for looking into this.