Rooms dissapeared

We've encountered the following issue:

The client, on their own initiative, tried to add one more person to the group of seven (they had four double rooms reserved) and attempted to add an extra breakfast — even though breakfast is already included by default with the room, but they were unaware of this. They made these changes through the website, and as a result, Hotelgest removed three of the four reserved rooms, repeatedly showing the same error.

The rooms were still part of the reservation, but they appeared as unassigned in the planning. Apparently, it wasn’t possible to reassign them for the selected dates because the system showed them as already occupied. I believe we had previously changed the rooms for this reservation (and they had received upgraded rooms) in order to accommodate manually entered bookings.

Since Hotelgest was unable to reassign them to standard double rooms as originally booked, the system was confusion.