Hi @IBS
In current version, the after order booking data is not managed properly so the rooms do not get free once an order is canceled.
So you will have to go to the order which is canceled and delete the rooms in that order.

But we are working on this issue in our new version and hopefully, you will get the solution in the upcoming version which will be launch very soon.

Hello @pascal
When you migrate the system, the whole system gets migrated. Hence to understand your issue we will need more details. And if possible then please share screenshots with us.