A kubernetes master for 9 Nodes on CX21 (old tariff) is using ~25% of memory. So that one was throttled.
Also some of the workers uses >20% on average. Makes no sense to me to book a vServer and not to use it's resources.
If Google translate is correct your link says CPU, not memory. I would be surprised by a memory trottle because I can't think of a sensible way to implement it and for example AWS limits CPU but not memory.
