When trying to add Korean text to a document, the text first appears in tiny text in the corner of a popup box that stretches across the bottom of the screen. Only after one character block is finished will it appear where you are trying to place it in the page.

It's apparent that the intent of this feature is to allow you to review what you're typing. However, the popup appearance does not seem to be customizable in any fashion, and the text is TINY. The effect is hugely distracting, painful to try to read, and beyond frustrating to the point I'm looking for a different PDF markup tool than Acrobat DC for Mac.