I am using a backend service that makes API calls on my behalf. About 9-10 days ago all of the API requests were fine and returned a result but starting yesterday any time I try to make an API request to my sandbox account it gets aborted with
Not valid http result json(upstream connect error or disconnect/reset before headers. reset reason: connection termination)
At the same time, I can make the same request with Postman/Insomnia, and this backend service also is successful making API requests to other services besides Square. It looks like Square does not allow requests from their IPs anymore? Is that even a possibility or a probability? Their customer support is saying that based on their logs it looks like the connection is terminated from your end.
P.S. I attached a screenshot showing what’s going on from my end on the service I’m using.