It sounds like you have two schemas deployed, one with a namespace and one without.
A message arriving with a namepsace gets a message type of http://www.iba.ch/cxml#cXML. A message arriving without a namespace gets a message type of #cXML.
The orchestration is subscribing to a message type of http://www.iba.ch/cxml#cXML and will not process any other message type.
If you wish to use messages without the namespace you will need to change the message type definition in the orchestration. The message that is received by the activation receive shape needs to use the schema without a namespace.