Getting daily spam calls from German numbers (+49 345…) – how to stop them?

For the past week, I’ve been getting calls every single day from German numbers starting with +49 345. The weird part is, whenever I pick up, there’s complete silence and nobody talks. I tried blocking them, but the numbers keep changing slightly each time (different last few digits), so blocking doesn’t help.

I don’t remember signing up anywhere with my phone number recently, so I’m not sure how they even got it. It’s starting to get really annoying.

Has anyone else experienced this? Any effective way to stop these kinds of spam/scam calls? Should I just ignore them, change some settings, or maybe contact my carrier?