Aperçu en temps réel sur Dreamweaver

Real Time Preview doesn't work well on any operating system. 😝

Instead, use Static Preview in Local Browser.  If you have pages containing server-side scripts, get a local testing server (Wamp, Xampp or Mamp for Mac). 

Go to Preferences ⇒ Real Time Preview ⇒ see screenshot.

Known issues in Tahoe that Apple needs to fix.

https://osxdaily.com/2025/10/10/stop-overlapping-text-legibility-issues-on-macos-tahoe-with-reduce-t...

https://www.macobserver.com/news/macos-tahoe-continues-to-face-severe-memory-leak-issues-even-after-...

Good luck.