I am really aggravated about this - I just called MHC again, and they said they are still having “system upgrade issues” but that I should be confident that hotels are receiving the reservations. If the “system” is having such a problem sending confirmation emails, I have no clue how they can be so sure that the “system” is transmitting these reservations to the individual properties.

They continue to downplay this - “well, you can see them in the app” - why would I trust your app since it goes down so often (including today) if I arrive to a hotel that can’t find my reservation? I’ve been saved by confirmation emails before and don’t appreciate the blasé attitude from Hyatt on this issue that has been going on for almost a full day now.