Some application windows resize slowly every now and then. This largely
depends on the speed of your computer.

Some application windows resize, but the inner content becomes garbled.
You need to manually resize the window a little bit and the content will re-appear.

Some application windows have minimum and/or maximum sizes and may not
resize correctly. In this case, the window may fall over the center dividing lines
or may not fill the desired size fully. Resizing the window manually will give you
a feel for how small or large a window can be resized. This is mostly an issue for
smaller screen sizes.

Some application windows have locked aspect ratios and may not resize correctly.
In this case, the window may not fill the desired size fully. Resizing the window
manually will give you a feel for how the aspect ratio is locked.

Some application windows are not resizable using Accessibility.
In this case, the window can not be resized using Split Screen