What could have caused Mattermost mobile alerts from happening after updates?

Our community / Team version of Mattermost was delivering messages to mobile devices without a problem until a few updates ago. Is there anything that would have stopped this from occurring?

We recently migrated the TPNS, and HPNS servers, which would have resulted in a change of IP addresses. I would suggest to restart the Mattermost servers and also flush the DNS cache for good measure.