We had similar issues with various plugin update errors that seemed random but only occured when attempting an update using the admin interface. In Cloudflare go to Speed > Optimization > Content Optimization. Check to see if Speed Brain is enabled. Disable Speed Brain and try your plugin updates again. For plugins that have already failed to update you might need to delete them and reinstall them even Speed Brain is the problem. We discovered the failure caused some plugin folders to be empty or had several missing files.
