Copy and paste will not work in Scheduler

I am having the same problem. For example, I have a premade text file with what I want the post to say, aleady all typed up. If I highlight and CTRL C to copy the text to the clipboard of my computer and go CTRL V to paste it, it should put that text in the space where I had my cursor - such as in the pop up box in the scheduler where you put your post text. But CTRL V does not work. I have tried copying from other files, other posts, other text from online. CTRL V does not function inside the scheduler. This is a big bummer, because it means I have to retype everything I have pre-prepared for scheduled content. It also means I can't copy and paste to reuse content from somewhere else (like from a blog post) or an older tweet or post from prior years.