Command block text does not scroll when holding shift

When trying to select text inside of a command block by holding shift and arrow keys, the text does not scroll.

To recreate - place a command block and enter something longer than the text box, click somewhere and try to highlight text that is past the boundary of the text box.

Usually the text would scroll.

Related note - the shift key acts like a toggle sometimes now in command blocks, I dont know if thats intended or not