Page jump on url anchor

Hi,
Thank you for your patience and for the link to your page, I see that you are using the Composite Products extension, I have tried to go through the documentation for the extension as it is not standard or free, and we don’t have assess to it, but besides the documentation I could not find a live example so I’m not sure if the redirect ID #gender or as you wrote: resets to the tab upon loading
can be disabled, as this is what is causing the “page jump”.
This “page jump” is the result of an ID in the URL and is a web standard, this is how all anchor links work, so from the point of adding an ID to a URL and that ID is in the page HTML, “jumping” to the ID is “correct behavior”, this is the ID of the dropdown menu.
But this ID doesn’t “reset” the drop down or any other options on the page, it only acts to “jump” to the option, which would be good if the option was at the bottom of the page and you didn’t want anyone to look at the product details.
You can test this by watching the gender dropdown carefully on page load when the #gender ID is not in the URL, you will see before it is added the dropdown says Choose an option, then try making a choice and remove #gender from the URL and hit [Enter] after reload and before the ID is added once again the dropdown says Choose an option.
So the added ID is doing nothing.
Since this is a paid extension you should ask the woocommerce team how to stop the ID from being added, unless to can see this option in your backend and can disable it.

Best regards,
Mike