Same thing here on a 5 night stay currently underway for which 100k points originally deducted in May 2019. Today a new deduction of 105k points was made and the original 100k points refunded (though hard to tell from the way my account activity showed it). Called MR titanium line and agent said it was because the hotel category had gone up ‘early’ ahead of the usual March 2020 changes. But that doesn’t make sense because a category change should result in 20k increase on 5 day reservation. The agent refunded 5k points to my account, but I am still not happy that I now need to babysit redemptions for such nonsense. This, combined with a very lousy promotion in fall 2019, makes me likely to start booking elsewhere.