Hi,
if you don't have multiple stores connected to your account, then Resource id #36 is your own store.
There's a caching in gromox for the "OBJECT_TREE" structure and when it expires grommunio-sync has to reconnect. Its default value is 1 hour. A higher possible value is 1 day (add user_cache_interval=1day to /etc/gromox/zcore.cfg).
grommunio-sync checks if the connection to zcore is still available in order to prevent the mobile devices from resyncing unnecessarily.
Check user_cache_interval in zcore for more information.