Upgrading to macOS 26 reveals a frustrating user interface flaw: resizing windows often fails when you grab the corner. This isn't user clumsiness but a design oversight by Apple. Developer Norbert Heger explains that while the new OS features a much larger corner radius, the window's active click area remains a small square, located far from the visual curve.

Most users instinctively click within the rounded visual, but 75% of that area lies outside the functional zone, causing the drag to fail. This disconnect between visual design and logical coding marks a step backward. Veteran Mac users recall when operating systems provided a clear visual handle for resizing, but modern design assumes users can grab any corner.

Now, the aesthetics of Tahoe's curves clash with the underlying rectangular code. This creates visual glitches, like scrollbars appearing to sit outside their containers. Apple must decide whether to adjust the active area or sacrifice the rounded look for functionality.

For now, users must click precisely to resize windows.