prevent pasting into browsers i haven't gotten to work, nor have confirms from anyone I've worked with: solutions partners, Microsoft support, regular admin users on the AIP yammer channel...needless to say support ticket still opened its at the stage where im asking them to prove to me this works in their environment, they havent been able to for 3 months...
and this comment in the blog post: "on supported browsers, including Microsoft Edge, https://learn.microsoft.com/en-us/microsoft-365/compliance/dlp-chrome-get-started?view=o365-worldwide, and https://learn.microsoft.com/en-us/microsoft-365/compliance/dlp-firefox-extension-get-started?view=o365-worldwide. Learn more https://learn.microsoft.com/en-us/purview/endpoint-dlp-using?source=recommendations&view=o365-worldwide#scenario-7-restrict-pasting-sensitive-content-into-a-browser-preview."
the chrome purview extension doesn't support prevent paste, theres no indication its supported: https://learn.microsoft.com/en-us/purview/dlp-chrome-learn-about