[ubercow13]

Also the resize cursor is completely unreliable, the cursor often doesn't change to the resize one when the mouse is over the correct resize areg. So it's even harder to tell if your cursor is in the right place before clicking. If you click in the wrong place it can have frustrating consequences, like activating another window or even clicking something inside it.

[re]

I have had issues with resizing Quick Look windows with their rounded corners on macOS for the last several major versions, well before Tahoe. The resize cursor indicator there also doesn't seem to appear at the correct location for the actual resize handles.