Wix uses Ajax, so the meta description and other page content is viewed by search engines like Google via the escape fragment of the page.
To see this content, you have to enter:
after your domain in the URL field of the browser.
Here is an example:
This displays all the page's actual content.
Google and other search engines read this fine with no problems, so you don't need to worry about SEO.
See below screenshot to see what I'm referring to – you can see that if I just look at the source HTML code of the page, it doesn't match or show my actual SEO meta tags or page content in the main HTML source code. This is because the actual page content is getting pulled from the fragment by Wix, which Google follows and indexes with no problems.
Here is the screenshot of the escaped fragment of my Wix SEO blog homepage: