Perfmatters is a great caching and performance plugin for WordPress. It has been found that it can cause issues with the WC Vendors Pro dashboard. This article will outline known issues and how to remedy them.
Duplicate products issue
Perfmatters has an option called Instant page that will prefetch a link speeding up the overall site speed. This is a great feature for some parts of the site but this can cause issues on the WC Vendors Pro dashboard.
It is best to disable Instant Page for the Pro dashboard page settings.
How to exclude Instant Page on a page/post
You can exclude Instant Page from running on an individual post, page, or custom post type. In the editor, on the right-hand side uncheck “Instant Page.” This will exclude the entire page from the script.