ᐅ Bathroom exhaust fan runs continuously! Either "loud" or "quiet"!

Good day.
I noticed in my new condominium that the Maico exhaust fan in the bathroom (which has a window) runs constantly.
When the light is on, it runs louder. When the light is off, it becomes quieter, but it is still running all the time!
My electrician says this is normal because the fan needs to circulate a specific volume of air as part of the ventilation concept. I only have windows with the above-mentioned ventilation slots in the frame.

However, even at the lower volume, the fan is already disturbing.
I cannot close the bathroom door because of the cats!
I can hear the fan at night as well.
And it is constantly consuming electricity.

Does it have to be this way? Or can something be done, for example, an additional on-off switch for the night?

Thank you very much
erika

Unusual, I have a bathroom without a window that only runs when I "stink."