taxonomy box dissapears when selecting a term

Hello everyone, i am troubled by a weird behavior of WP lately. I am using a colorlib theme and several plugins and when i add a new post or edit one and i add a new term in a taxonomy after checking the checkbox of the term, the entire box dissapears! If i go to screen options i see that the option to show the corresponding box is unchecked and if i check it back the box appears and keeps the term i checked.

I am thinking that this has to be a javascript maybe from the theme (didn’t find anything) or from a plugin(again didn’t find anything), does anyone else came across this ?

Thanks
Tolis