Google can return a soft 404 error for a number of reasons, such as if it thinks your site pages contain little or no original content. They can also be caused by technical issues, or if you recently deleted a page from your site.
It is important to note that a soft 404 error does not affect your other pages' rankings. Soft 404 errors that appear in your Google Search Console may be old and no longer be relevant. Errors that appear for pages such as your deleted product pages or deleted blog posts may render a soft 404 error; this is normal behaviour and will be resolved eventually.
If you receive a soft 404 error message for a URL:
Review your affected pages:
If your affected pages do have meaningful content use the URL Inspection Tool to request reindexing for your page by submitting your page's URL.
If the pages are not supposed to appear in search results (e.g. if you have deleted it from your site) you can ignore the error message.
Review the content of the affected pages:
Soft 404 errors are sometimes caused by a lack of organic or unique content on a page. This is a preventative measure performed by Google, so that these lower ranked pages won't be considered spam.
To resolve this issue, you must optimize your affected pages' content for SEO, ensuring that your pages' content contains unique and organic text. Don't forget to add alt text to your images too.
Tip:
Learn more about optimizing your site's content for SEO.
This article is credited to the Wix team - https://support.wix.com/ and we thank them for that!