I have spent quite some time on fixing this comment issue. My skills with PHP is very minor, though I do have some understanding of it. To my knowledge what happened is that after I updated to a newer WordPress version, something broke about the comments php file for the theme I use. After looking into the code itself I basically kinda gave up after some time and decided to roll back around 1. However not much comments were lost in the rollback, but now using the previous version of WordPress has the comments working again.