This article may turn out helpful in resolving persistent issues in Google sync.
It is known that sometimes, even though the actual calendar sync is pulling the appointments from the server to the database in the phone, these appointments do not appear in Sailfish Calendar. Likewise, the contact sync may not do its job.
The following is a kind of reset of the sync utility. It does not do any harm to the appointments or contacts.
DELETING SYNC STATE FILES
Delete the sync state files of calendar and contacts (respectively) with commands
devel-su -c rm -f /home/nemo/.local/share/system/privileged/Sync/gcal.ini devel-su -c rm -f /home/nemo/.local/share/system/privileged/Sync/gcontacts.ini
The next sync should be a "clean sync" which should pull in all of the events from the server.
Trigger a sync cycle by opening up "Settings > Accounts". Then long-press either the account you want to debug. Tap Sync in the pop up menu.
This article explains how to collect logs concerning the sync of various accounts.