About Ads in Laptop

Hello!!! Recently i downloaded Brave in my PC( HP LAPTOP) and watching ads.
I am Having a feeling that only when i move the cursor or doing something, then only ads are appearing. if i am keeping my laptop on and going somewhere like 30 minutes, no ads are coming after i am back and moving cursor then ad is coming.
I want to know is it common or i have to make some changes so that ads will appear on time without my interference.
2. Ads will appear only after opening the app? No Ads will come if it runs in Background?

Genuine answers please. no Bullshit.

Ads don’t just come by opening the Brave Browser. You have to be constantly active on it by doing something.

Oh thanks. That’s what i wanted to know