“Unknown Caller” keeps calling me, I can’t block the calls

Anyone else been getting an influx of unknown numbers calling or specifically « Unknown Caller » calls? I get these Unknown callers almost every day, and up to six times a day. They never leave a voicemail, and off the two times l’ve picked up the calls drop almost immediately with no words exchanged. I figured out how to silence them on my phone, but it’s still really odd and you would think after weeks of not picking up they would give up. This must be a scam attempt right? Does anyone know what this could be or how to stop them? There isn’t any option to block because no number is provided. Any input is appreciated, thanks.