“Nothing found” is not the same as “Page not found” – If I make up a bogus URL like borclo.com/somethingelse I get a different message, “Oops! That page can’t be found.” The “Nothing found” message often means that it’s not finding any posts associated with the author.
That being said, if I go to https://www.borclo.com/store/borcloph/ (using “store” instead of “author” it does display a banner image and products. I accessed that archive by going to a product on your store, clicking the “Vendor Info” tab, and then clicking on the vendor name link.
I’m not certain, but it would make sense that by installing WooCommerce it would use a “store” permalink instead of “author” since selling is the goal of the plugin. Perhaps “author” would be used only in the event of creating regular posts (blog-style content, not products). I don’t see a blog or other posts, so that may be why it’s showing “Nothing found” on the “author” archive page.
So perhaps there is no issue, WooCommerce may just handle it differently than you were expecting. ??
If there is an issue I’m not seeing, the best option may be to contact the WooCommerce support team to see if they have any ideas, as it’s not a broad WordPress issue. Here’s the link to WooCommerce Support (you’ll have to log in to your WooCommerce account).
Best of luck!