Today, my grandma's application for a travel visa has been rejected. She has a refugee travel document since she's been living in Germany. She's been living there for 30 years. Her sole purpose is to visit her children who are US citizens. Also, it's not the first time she went to the US; she's been there about 5 times.
Considering all these facts, the visa should have been granted. She was told that there are new policies in place prohibiting all people with refugee travel documents from entering the United States and there are no exceptions.
I didn't find anything on the internet. What has changed that would result in her visa being refused?
Considering all these facts, the visa should have been granted.
That is incorrect. Nobody is entitled to a non-immigrant visa however strong their application credentials.