I have now bought a 60s cable in red (SN: 60scab0000103). It looks really gorgeous and everything works fine, but I am a bit worried:
immediatedly after unboxing the phone, I tried to dial and the disc simply stuck in place and did not return. I had to give it a push.
After that all worked fine, but I wonder if this is a problem that will happen again.
Is this a known issue? What should I do?

The dial discs contain several greased parts for smoother operation. It is possible that some of the grease gets compacted during transport due to the shaking that inevitably occurs on route from Asia. The grease is however distributed evenly again after a few dials.

So this is not a real problem and what you have done is exactly right. After giving the dial disc an initial push and dialling a few times, all will work smoothly and reliably.