We had booked a trip to Maui which included a five night stay with a five night Encore package followed by 12 nights in a Napili tower. I routinely watch my reservations on the Marriott app (thankfully) 36 hrs. before leaving I find my arrival date changed from Jan 17 to Jan 13. Always have printed a hard copy until now when I did not as the reservation popped up on the app as I was speaking to the representative. I was on the phone for 5-6 hrs before finally getting things straightened out. Found out that the reservation got changed at the Ritz Carlton on the Friday before my arrival.
The biggest problem was the Encore group which booked the first five nights had the dates as I did but the hotel had me as a no show. Both places still had the same confirmation number, neither party would talk to the other as Encore had the correct dates but the reservation at the hotel could not be altered because of the no show status (?).
Finally Margaret at the Maui Ocean Club got things straightened out as we were leaving for the airport.
The trip turned out great, the Ritz at Kapalua was terrific and Maui Ocean Club has always been a great time for us this being our fifth trip since 2011.
Great lesson learned, always have hard copies and never stop checking details.