I had a previous topic with a similar situation, but the details are different this time.
I have an External API Global set up with monday.com. It has bee working for months. It stopped working briefly (returning 403 errors), and disabling IPv6 fixed it. IPv6 remains disabled.
Today I noticed the data was missing again. Checking the API Tester, now my API is returning a 400 error. According to monday.com documentation, this is usually malformed query or malformed JSON.
Again, this had all been working for many months. When I replicate the setup I have in Postman, with the same headers and the same GraphQL query, everything works (as it always has).
In Cornerstone/Pro, I am only seeing the error number, not the error description from the API endpoint. I don’t know how to troubleshoot this further since it works in Postman.