After the reinstall I had two flights without problems. However the third flight revealed the discussed problem again.
Something I have probably noticed may cause the issue is the elevator trim. For the third flight I've trimmed the elevator from the top end of the green band into the middle of the green band. The fourth flight (without touching the trim on ground again) worked again without the problem. I played around randomly with the trim setting before and had the "stick to the runway problem" also randomly. Maybe this has caused the issue ...
Maybe someone can confirm this investigation independently.
