Some app or component installed or uninstalled must have mucked up the dropdown lists functionality all over an odoo installation.

They only show one line's worth of content and it's a pain to scroll in them. The keyboard up and down arrows won't even make sense as they go off the limits of the dropdown list box. See this picture:

the expected behaviour should be like this (tested on a fresh installation of the same version of oddo - 16)

Can someone point me to the place I should look into this to reset these DDLB's to the original? Or else just how to resolve this pesky issue.

Thanks,