In the Edit window, if you hover over the close button, the left side of the “C” in “Close” gets clipped off.
Also, if you click and hold “Close” and drag your cursor off of the button before releasing, then the button remains highlighted.
On a related note, the button styling in the Add window is different, but I would expect them to be the same.
Version 2.1.65 (aa9a734f)
Python 3.9.15 Qt 6.4.3 PyQt 6.4.0