In some instances, there are outbound Server Message Block (SMB) calls from Dreamweaver while using protocol relative URLs.
Environment
Dreamweaver 19.0 on all supported operating systems.
This behaviour is seen when you have HTML/PHP documents, with protocol relative URLs, to refer other resources in the document.
When the HTML/PHP documents are deployed, the HTML file is accessed through http or https protocol, which results in the protocol relative URLs also being accessed as through http:// or https://.
However, while working locally in Dreamweaver, the files reside on local disk. The HTML document loads into the browser component (Chromium Embedded Framework) as file://path, which results in the other protocol relative URLs being interpreted as file://. Similarly, a URL similar to //api.company.com can be interpreted as file://api.company.com resulting in unexplained outbound SMB calls.