mercerik, thanks for your suggestion. The problem is not related to the device or iOS settings, vibrations are still activated. Actually it was my first concern, that the device may broken, when the feature disappeared. But as the colleague suspected, It seemed that I have been part of a testing group.
@Sukanta_Biswas, thanks for your quick reply. This means I have coincidentally been in the haptic feature testing group since I started to play. Then it makes sense that the feature disappeared suddenly. Are you part of the dev team? Or do you know if it’s possible to give them some feedback for those kind of test rollouts?