I think the issue is because 192.168.1.9 is not considered as a secure context and so your browser doesn’t load the SubtleCrypto API ( https://developer.mozilla.org/en-US/docs/Web/API/SubtleCrypto ), while http://localhost (or 127.0.0.1) is considered as secure.
try typing isSecureContext in the webconsole, if it returns false it means that you need to serve this endpoint via SSL