Welcome to our forum, @pastewka! Have you tried restarting Word, signing out of and back in to Paperpile, perhaps uninstalling and reinstalling the plugin? Check out this troubleshooting guide for more scenarios/suggestions.
If that doesn’t do the trick, please send us the plugin log file so the team can investigate further. The easiest way to find the log is through the Paperpile tab on Word > Settings & Tools > Preferences > Send Log File, then attach the paperpile-logs.txt file to your message – preferably via chat or email (email@example.com) since those contain some of your private information.