Thanks Radu, this works as a temporary solution. However I’d really like to get things back to how they were with the styles available by way of a drop down when adding a menu item (Screen shot of what I mean is attached, and here are the instructions for how I should be able to do this: https://forums.envato.com/t/kleo-theme-how-to-create-buttons-in-extras-header/115955).
Manually doing this with CSS every single time I update my navigation is a bandaid – I hope you understand!
Thank you for your help so far, but please advise.