Feedback for students

I am looking for support for the teacher inquiry I received below. Please let me know how to provide support.

I've noticed one thing: the stuff that is sometimes deleted is the numerical grade and whatever I have typed in the "add feedback" box. Things I have written directly on the submitted file using the pen tool, or post-it notes I have left on the actual file are never deleted. So, it just turns into a matter of paying attention each time I hit the "commit evaluation button". On the ones where I have typed something in the "add feedback" box, I ctrl+c copy it before I hit submit, so that if it erases, I can just ctrl+v paste it.

Is this best practice? Is there another approach that would work better?