Missing buttons in Submissions list

With OJS, some buttons are missing for the ‘main user’. i.e. the person who is overseeing all the entries - having assigned the review to himself the buttons are missing. However, the buttons are visible for the admin. The ‘Review’ button as well as the Dropdown is missing in Submissions view. See how in 135 the buttons are missing in the bottom image.

Any ideas how to solve the issue.