You could use Do Not Disturb, and make an exception for calls that come from any of your established contacts. At least this would solve the problem with calls overnight.
Ugh now the restricted # is calling at various times of the days. Super frustrating that it can't be blocked
Not sure if this will help you, but...
I'm using the Samsung dialer on my unlocked S22U, and under 'block numbers' I have the option to block 'unknown/private numbers'
I never looked for this on my N20U, but I'm guessing it is the same. Also not certain this would actually yield the result you are looking for, but it looks promising to me. See if you have this option and let us know.View attachment 343185