You need to trigger the sync manually from Clippings Manager on the second PC - click on the sync button next to the Synced Clippings folder. For more help, see the Sync Clippings page at https://aecreations.sourceforge.io/clippings/sync.php

If you are having further issues, please post to the AE Creations Help and Support forum: https://groups.google.com/g/aecreations-help