Web links don't open in Safari 18.0 on macOS Sequoia 15.0

[davidfokkema]

Using App.open_url() in a Textual app opens links from the terminal, from Chrome, from Firefox, but not from Safari on my machine. I don't see any indication that pop-ups were blocked. If I allow pop-ups from localhost (where I serve the app from) then it still does not work. I see no javascript warning or errors in the web dev console.