Ok, thanks.

Dillen:

The antiskating effect will cause a drag of the tonearm away
from the platter center, that's normal.
It's to compensate for the physics causing a drag inwards (towards the center) when playing
a record. It's a question of friction and speed of the media being lower towards the center.

 I would not think that in this case the drag of the tonearm away is caused just by the antiskating effect... Because each time it did go just back precisely to the arm rest position. I would expect the arm to be lifted up before that.

Peter:

B&O recognised this problem as the range of decks that took over from the this series have a record detection mechanism - it weighs the record and if not there the arm will not drop.

Yes that is a good idea to check the weight...

Anyway, now I know and it is not difficult to remember about it.

Thank you very much

Adam