Cannot call one particular number - Iphone 11Max Pro

[ASaye]

Starting yesterday, I suddenly cannot call my veterinarian's office. I choose their number from my contacts, and I get a recording that says "You are not authorized to make this call. Contact your administrator." No error number or reference at the end of the message. I try inputting the number manually, I tried repeatedly (4 or 5 times in a row), and once I tried searching for their website on Google and hitting the "call" button from that page (which worked...despite being the exact same number that's in my contacts). Dialing from the Google listing worked the first time I tried it, but not the next. Tried it with and without the 1- in front of the area code (normally works without it). 

This is the RANDOMEST problem. No other phone numbers have done this to me. I am in good standing with my vet, by the way, and am not blocked. Their calls to me come in just fine. Any ideas?