The app that I developed was working perfectly for almost a year now until Sunday; then whenever it tried to call the API endpoints for the various shops that have the app installed it would return the message like this:
Failed connect to xxxxxxxxx.myshopify.com:443; Connection refused
I've got in touch with someone from support and they don't seem to know what the issue is and they suggested it could be my network issue. But I have the same app done for BigCommerce and that's working fine. I also tried doing a curl to the regular shopify.com domain and that's OK too.
For the time being I've updated the code to use a proxy server to make the API calls and it's working again so it's nothing to do with the app either.
Is there a process to know if my server IP is actually being blocked and if it is for what reasons? Otherwise the proxy server that I'm using might also end up being blocked one day without me knowing when or why.
Are you able to provide me with an x-request-id (found in the response headers) from one of your recent requests that failed or generated this specific connection error? I would be happy to look into this a bit further for you.