Purview endpoint DLP cant block file upload to web.whatsapp on open in app mode chrome browser MacOS

Hi,

I think your observation points more towards a limitation of the Chrome PWA context on macOS than an issue with the DLP policy itself.

The key indicator is that:

• Uploads to WhatsApp Web are blocked in a regular Chrome tab.
• The same upload is allowed when Chrome runs WhatsApp in "Open as App" (PWA) mode.
• The same PWA scenario is intercepted successfully in Microsoft Edge. [Purview en...munity Hub], https://learn.microsoft.com/en-us/purview/dlp-browser-dlp-learn

My assumption is that Purview Endpoint DLP does not get the same browser/app context from Chrome PWA on macOS that it gets from Edge, where Microsoft has much deeper native integration for DLP and browser protection. https://learn.microsoft.com/en-us/purview/dlp-browser-dlp-learn, https://learn.microsoft.com/en-us/deployedge/microsoft-edge-dlp-purview-configuration

For customers with strict data exfiltration requirements, I would not rely on Chrome PWA protection alone. A more robust approach would be:

• Use Microsoft Edge for Business as the corporate browser.
• Combine Endpoint DLP with Conditional Access and Defender for Cloud Apps.
• Treat WhatsApp Web as an unsanctioned or high-risk application if appropriate.
• Validate whether the behavior affects all Chrome PWAs or only WhatsApp Web before making policy decisions.

Also, before enforcing Edge organization-wide, I would check for business-critical Chrome extensions or application dependencies on macOS. In many environments, the browser change itself is easy, but the surrounding ecosystem needs to be assessed first.

Would be interested to hear whether Microsoft confirmed this as a known product gap or an unsupported Chrome PWA scenario.