Safari 17 hangs on opening a new link if no windows open

### The Problem On opening a new link when there are no Safari windows, but Safari is already active, Safari will hang (complete with beach ball) for ~10–30 seconds. ### Reproduction Steps 1. Have Safari **open** but with no windows 2. Click a link in any app, open a bookmark with Alfred, or enter a URL with Alfred or Spotlight. 3. If Safari opens **both** the link and a blank tab, Safari beach balls for between 10–30 seconds. ### Specs - Safari v17.1 (19616.2.9.11.7) - macOS v14.1.1 (23B81) - MacBook Pro 14" (2021, M1 Pro, 32GB RAM) ### Things I Have Tried - Disabling all extensions. - Occurs with or without a network connection. - Doesn't reproduce on a test user account. - Clearing website data: **Settings > Privacy > Manage Website Data > Remove All**. - Setting Safari as the default browser (previously BetterTouchTool was) from **Settings > General > Set Safari as Default Browser**. - Quitting BetterTouchTool just to be safe. - Restarting my Mac. ### Things I have noticed - Whenever the hang happens, I have noticed that Safari will open a second, blank tab. So, although I have only clicked one link, two tabs open. - In Activity Monitor, the Safari process says it is using ~100% CPU when the beach ball happens. All the other Safari processes (extensions, networking SafariLaunchAgent, etc) seem normal. - Frustratingly, it doesn't happen every time! It will be fine for 3-4 fresh links and then the problem will reoccur. It doesn't matter what URL I go to. It doesn't happen at the same point. Sometimes happens before the page loads, and sometimes after the page loads. But always within about 60 seconds of the new window opening. - Clicking on Safari in the dock to open a new window, and entering the URL into the address bar, doesn't cause the fault. I am a bit stumped about what to try next. Every time I think I've narrowed the culprit down, I manage to reproduce the problem. Suggestions for things to try or ways to narrow down the fault gratefully received!