I use bin 2 for guiding with an ASI174MM Mini camera. Latest KStars (3.7.0 from Ubuntu PPA) resets this setting to 1 on each new session most of the time. I have to change it to 2 manually each time. A couple of times it actually started with 2 on its own. I have no idea how those sessions were different from others.
Several older versions worked fine in this regard.
Tell me if you need any particular verbose logs or files.