
Safari 16.1
Apple has released Safari 16.1 for macOS 12 Monterey and macOS 11 Big Sur with patches for four vulnerabilities that could disclose sensitive user information, lead to arbitrary code execution, or enable interface spoofing. You can download Safari 16.1 only via Software Update. (Free, various sizes, release notes, macOS 11+)
This fixes the tab problem that @Simon identified (tab groups not starting to load when clicked).
Indeed it has.
…and also the weird duplication of tabs that happened on dragging a tab to a new window.