The issue is the parallax on the section where is the dropdown.
The parallax effect adds a overflow hidden on the section, and this is obrigatory and can’t be removed for the parallax effect. As the dropdown is inside the parallax, the z-index don’t have effect.
Unfortunately doesn’t have an alternative for that, the only way is remove the parallax effect and substitute by a simple background image.
Thanks Rodrigo, that fixed it, although it’s going to look a bit stiff as i wanted to make a more lively background. Does the parallax effect break the tables as well if i were to add it to a table section background ?