I suddenly have been getting this problem too. Here’s the wierd part. I am on WIN10 and use Console2 for tabbed-command windows. It lets me pass in commands which I use to start up my nodejs, mongodb and expo services so I can do my development.
The only thing I can think of is that I tried installing react-native-pdf following these instructions shortly before it started getting loopy on me last night. The instructions had some command that linked react-native-pdf to react native. But that doesn’t explain why it works in a non-automated command terminal vs. one that automatically fires up the npm start command.