Ads popping everywhere on Android 10

I have a simple Oppo A15 running Android 10 ColorOS 7.2. It worked fine for many years but a week ago I started having some issues with ads popping everywhere. When using Chrome or any other app; as I am writing this message it happened twice. The ad is basically as if it's a new app that opens. The content of ads is not really relevant I think. Any suggestions? It's becoming more and more annoying