Thank you so much for the great and detailed review — we are very happy that you enjoy using our bread slicer and that it makes cutting your sourdough bread so easy!
We also really appreciate your feedback regarding the suction cups. In general, suction cups hold reliably only on smooth surfaces, as rough surfaces do not allow proper vacuum sealing. This is a common behavior with suction cups of this type. Many of our customers simply place a smooth surface underneath in such cases — and then it works perfectly and stays stable.
Thanks again for your honest feedback and your recommendation! We wish you lots of joy with baking and slicing bread 😊