That the scrollbars are different for each tab is intentional - as you wrote, it's because of different entry heights. If you for example change the replacement age of a machine, the same will happen.
But it's weird that the window extends below the bottom of the screen. The window max size should be limited at <user-screen-height-in-px> minus 250 px. If you drag the window around, is its total height still bigger than your screen? Or was it just positioned in a way that the lower part of the window was out of screen?