If you own a OnePlus phone of any generation, you might know that there is no possibility to block calls from unidentified numbers (private, unknown, hidden) out of the box. If you search for the solution on the Internet you will possible find a lot of forum posts suggesting to install some third-party apps from dubious developers.
Some of these apps are paid, some are free but will bother you with their ads. But the worst thing about call blocking apps that they often can’t actually block all unwanted calls including calls from unknown and private numbers.
Not so long ago, I also bought a OnePlus phone and quite soon I noticed that I could not block spam calls from restricted numbers. I was unpleasantly surprised and began to look for a solution to fix the issue. Surprisingly, I found a solution from Google. And by the way, it’s free and without ads.