Using Logos 8.0 on Windows 10 I noticed that I was frequently losing my place in a Sermon Document as I checked other resources.
It seems that it changes position if I hover my cursor over the scroll bar - even if I don't touch it
The screencast at https://www.screencast.com/t/fgabyS2eG demonstrates this.
I seem to remember this being a problem before but thought it had been resolved.