if it worked on Damus, but not other clients, it sounds like it's a CORS issue. 9 times out of 10, it's always a CORS issue.
Discussion
What’s the resolution if that’s the case??
I’m currently using cors parameters copy pasta’d from w3docs.com:
Header set Access-Control-Allow-Origin "*"
Header set Access-Control-Allow-Methods "GET, POST, PUT, DELETE, OPTIONS"
Header set Access-Control-Allow-Headers "Content-Type"
…SSL absolutely necessary or nah?