Woodmart select elements on Firefox developer edition

Hello,
looks like there is an issue with all the stylized selects in woodmart (like country select in checkout page), for example
go to the woodomart demo,
https://woodmart.xtemos.com
add a product and go to the checkout page
https://woodmart.xtemos.com/checkout/
here click on country select and then scroll, the options will stay fixed,
after that click anywhere and click again on the select it will popup and diseapear instantly
so multiple issues
i’m on firefox developer edition 80.0b2 (64 bits)
i have disable all plugins on firefox and it’s still the same
regards