I discovered the issue. If Windows text sizes are set to anything other than 'Smaller - 100% (default)' Epicor will do some odd things, like lose scrollbars and hide text in text boxes. Text sizes can be adjusted under Screen Resolution > Make text and other items larger or smaller.
We recently had some folks get upgraded monitors and they've been playing with the resolution and apparently found a sweet spot with high resolution, medium sized text. Unfortunately Epicor is not compatible with anything other than the Windows default text sizes. It makes sense, but because end users change the settings in Windows, they don't make the connection that they are impacting Epicor.