Marriott introduced peak and off peak pricing in September 2019. Stays booked before that date were supposed to keep the same pricing they were booked under, unfortunately there are now many data points of users having their stays automatically cancelled and rebooked with the more expensive pricing taking effect.
For example Flyertalk rylan had a booked for a couple of nights in February for 100,000 points, they received an e-mail in early January with a booking confirmation with 120,000 points being charged. After checking their account they see the stay for 100,000 points was cancelled and then rebooked for 120,000. This is despite them making no changes at all to their booking. It looks like Marriott is fixing this issue when you call them, but I wonder how many people won’t notice until it’s too late (or won’t notice at all).
I suspect what is happening is some sort of IT issue rather than something purposefully malicious but that really doesn’t excuse this type of mistake in the first place especially when Marriott has been made aware of the issue and has neither fixed the issue or proactively checked accounts to ensure this error is fixed without a response needed from individual loyalty members. I also haven’t seen any data points of people having this happen when the pricing decreases.
I’d recommend everybody check their Marriott accounts to see if this issue has affected any of your existing bookings (you can also see if your stays have decreased in price and rebook those). If this happened to me I’d be pushing Marriott for additional compensation as well as it’s simply unacceptable to charge a higher price for no reason.
Hat tip to TPG