Is there anyway to block private or unknown numbers?
There is no native way to do so on most Android phones. The singular exception among Republic compatible phones is the LG K30 but I don’t think you have that phone (correct me if I’m wrong).
Otherwise, you might find a call blocking app in Google’s Play Store that does the job. I’m sorry to say I don’t have a specific suggestion for one. Hopefully, someone else will chime in on that.
I thought as much well if anyone has a recommendation.