Thanks for your replies and your appreciations. Even if they explain different reasons.
Finally I got the reason and the solution: I replaced the appron links by taxiways. It's really a fundamental unterstanding after running FS9 for fifteen years!
BTW, it doesn't matter whether the hold short mode is as narrow as shown above or not. In some of my Afcads they are almost over the runway.
Anyway, thanks for your help. and I hope, my thread didn't include scamming intentions ...