- I added the Content-Type: application/json header to my Production Resource Configuration and saved.
- I switch to Staging to add it again. The value is already present; I just added the key again and saved it.
- I confirmed the header is NOT being included in Staging requests.
- I go back to my staging configuration and refresh the page to confirm the header looks good and it does.
- Header is still not being included.
- I delete that header and make a new (identical) one and save again.
- Now the header is included.
This tripped me up a few times this week, but now I make sure make a 2nd header and delete the first one that was prefilled.