Magic Mouse stumbles faltering

I describe this here in case someone comes about the same problem. I already solved it but after Apple Support was not able to help.

I had a new Mac Mini 2018 for a week when suddenly the also new Magic Mouse began strange behaviour, as if a hair was on the sensor, but it was clean. Also different surfaces made it work differently, mainly it mas not well moving and inprecise. On my Macbook it worked better, but inprecise too.

I removed any other source of radio signals without change. But then I remember I installed a new USB (not powered) hub the other day. And as soon as I removed it, all worked flawless.

Now, one would usually not think about USB when having a problem with a bluethooth device. I don´t know the connection here. But instead of conectinhg that hub directly to the Mac Mini, I connected it to the thunderbolt drive. This worked. I have other hubs connected directly but with extension USB cables in between. I don´t know if the distance makes a difference. The problem-hub ( ICY BOX IB-HUB1409-U3, 4x USB3.0 Hub, TypeA ) has a short cable.