small bug in course and possibly other post areas

This is more of a feedback item/bug report, I couldn't find a better place for it, I hope this is the right place.

I'd enrolled in one of your academy courses and noticed that when I entered text into the discussion page, if I used the back/left arrow (not the backspace, the actual arrow key) it went back to the previous page in the course area, and not back a character as one would expect. To make it worse, everything I had typed into the text box was lost.

Just in case you want it, the specific page this occurred to me on was:
https://premium.wpmudev.org/academy/courses/wordpress-development-for-intermediate-users/units/course-introduction#module-1106203