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I suspect that the firewall on the Dell laptop may have cut off communication on the network port required for the syncing.
Or, perhaps, the syncing process has failed on the laptop.
(Why the laptop? I'm not sure... but the question could be settled more surely, if you look on the main account, the server side of the meetings or appointments, which is supposed to sync with the two local devices, and see whether the Note 4, or the Dell laptop's, changes are syncing with it.)
(Unless, of course, you set up syncing to go directly between the laptop and the Note 4... in which case the laptop is still a reasonable place to start.)
Let me know more about how the syncing is supposed to work, and I will advise you further.