Studio monitor noise

Hi

Ive purchased Cubase 13 a while ago, ive also purchased the Steinberg interface UR12 wich is enough for my need.
Now i have some kinda white noise on my speakers when connecting them, also if i move my mouse, with every move the noise gets stronger.
The right drivers are downloaded, ive replaced the cables, played with the volume, adjusted settings… but still the same noise.
If i use my headphone on the interface,.then i dont have any noise problem.
Also i dont have any problem if i use the speakers for mixing records on a Pioneer DJM700 mixer.
The speakers are pretty old but dont think that would be a problem,.its an active speaker, Yamaha H80m.

I hope someone can help me causse its pretty anoying…

Thnx in advance.