Iphone blocks calls randomly

I loaded contacts back onto phone and tried the above suggestion blocking unknow callers. It worked for one day then back to blocking calls. I see others post this same issue on the internet but no real solution. At this point a new sim card is all I can think of?1?!? only thing not tried. Next, a new phone number I guess? All the obvious stuff is not working.

Thanks I will give it a try and let you know.

NOT RESOLVED!!! I clicked the button by mistake. callers still being blocked as detailed in origianl post.

yes. Followed the procedure more than once. Soo very strange. Seems to block in alphabetical order this last time at least. Did not notice the prior times.