I received a room upgrade when I checked in. On Saturday, the 26th, when I returned to the hotel at night, upon opening the door to the room, we noticed a strong smell of something rotten. Upon investigating, we noticed that the strong smell was coming from the bathroom drain. I called the reception, who sent an employee, who poured a bottle of liquid (in an attempt to neutralize the strong smell), without having any effect. The air in the room was already filled with the strong smell. I requested a room change, which was granted, with the help of another employee who carried our luggage. However, the upgrade previously offered was not maintained, and a downgrade occurred.