Hi Chris,
So sorry for the trouble here!
We have indeed seen this pop up every now and then and, in most cases, it was due to the way that the calendar importing the events reads .ics files. The .ics format is pretty limited in a lot of ways and different calendar applications choose to calculate times and locality in their own way.
Sounds like changing the timezone settings in WordPress did the trick. It’s still a little unnerving to not know why things stopped working. Have there been any changes to your site since the time things were working and then stopped? For example, were any plugin updates (including ours) installed or WordPress itself was updated? How about to the Outlook application itself? Has it updated in that timeframe?
Either way, I am happy to hear that things are working.
Thanks,
Geoff