Hi,
Do you have some kind of SEF extension, like SH404SEF ( 4SEF ), or JomSEF, or others ?
Something strange with your results is that even on the live website, some URLs don't have the id of the category in the URL (like the beakers ptfe). Normally, either all of them should have the id or none of them.
This indicates that you probably activated the "force canonical URLs on listings" setting of the HikaShop configuration:
www.hikashop.com/support/documentation/5...ig.html#features_sef
And in that case, the URL used is the "canonical URL" that you configured in the settings of the category, even if the URL there is invalid. And so, if you setup a category with a canonical URL using the alias of a menu item, and that something changes with that menu item or with some SEF settings, the URL would then generate a 404 error.
For example, I can see that you have the "category SEF name" setting set to "category" on your live website. If you changed that setting on your local website, then all the canonical URLs of the categories with that "category" SEF name would be invalid instantly.
Could you provide a screenshot of the "SEF" section of the HikaShop configuration page on your local website ?
What if you empty the "canonical URL" of a category and then refresh your frontend, and access that category ? What URL is now used ? Do you still have the 404 error ?