There may be many factors that could result in your files not successfully being uploaded to Google Drive.
A few to consider:
- Caching plugins: At this time, we know that certain caching plugins like WP Rocket may prevent normal functionality of the plugin not allowing files to be uploaded to Google Drive. Please disable all caching plugins and test to see if this helps. If so, please try swapping your caching plugin for a different one which may not cause problems.