How to get Safari to display CORS pre-flight OPTIONS requests in the dev tools network tab?
IIRC they used to show up, and I know the requests are being made as we can see them logging on the server.
We had the same problem suddenly occur with Chrome in the last few weeks (around Chrome 79/80) and had to force it by setting chrome://flags/#out-of-blink-cors to disable
chrome://flags/#out-of-blink-cors
disable