On iOS Safari on my iPhone 12, in the Research tool, trying to select a lens using the dropdown results in the dropdown going off the top of the screen - so I can only select the last couple of lenses.
The dropdown should be fully visible on the screen with all lenses selectable
My request would be to use native dropdown (select) elements. These are nicer to use, offering better/consistent UX, built-in accessibility, and avoid bugs like these happening.
This is a very simple dropdown so there's really no reason not to use a native one, in my opinion!