ok so the problem is that you have section tags as children of your form instead of putting the form elements (like textarea and submit) as children.
I would try the following in order:
change all section elements nested inside the form to ‘div’ elements, retest. if that passes, then that is the least amount of coding change you need (I would imagine).
if not, go for a more drastic change and dump the section elements entirely and re-test. If it passes, fix your css to make it look the way you want again (major changes will be needed).
Note that section tags are not used inside forms because they indicate unrelated parts of the page (or very loosely related). So rethinking these, even if they were not causing a problem, would still be a good exercise.