Mail 1 and Mail 2 were updated to Kerio 8.32 which uses an updated version of MS Activesync. Your iOS device (iPhone, iPad) might have been set up with Activesync. If calendar events do not appear:
Wait for a few minutes. They may come in as the update is applied.
If the calendar(s) do not appear after five minutes, check "Calendars" and make sure the calendars that are missing are selected. If they aren't, select them. Again wait a moment.
If the calendar(s) still do not appear, go to Settings, then "Mail, Contacts, Calendars." Turn the Calender syncing off (dismiss warning), wait a moment, then turn it back on.
That should correct the problem.
If you require any further help, please open a support ticket.