Hello @fernashes and thank you for your answer.
I haven’t been able to solve the problem. Apparently, on the page loaded in a desktop device you can easily use the dropdown fields at first. But after scrolling down the dropdown selectors list show out of place. On mobile devices this makes the navigation impossible.
It happens so far in all devices and browsers.
I suspect that the issue is originated with theme incompatibility. I am working with a child of Astra Theme. The problem is when I upgrade the parent theme WordPress ignores the child styles BUT is solves de Woocommerce dropdown problem. So I believe I must solve this problem first, for that I have created a different topic:
https://ww.wp.xz.cn/support/topic/child-styles-not-overriding-parent/
Thank you