Gaps between dropdown items

Hi,

There are blank gaps between dropdown items of the product price switcher.
You can see this screen shot: https://australianbio.com.au/wp-content/uploads/2024/07/Gaps.jpg

This causes that when we mouse the mouse pointer inside the dropdown, controls underneath the dropdown are activated focus events.

Could you please help remove these gaps, an CSS or code to solve?

Thank you so much.