Steps I took to reproduce the issue:

• Get the reservation for the user using /api/v2/reservations endpoint - check the reservation_id

{
"consumer_id": "qtcreator",    "consumer_installation_schema":"commercial",    
"consumer_version": "16.0.2",    
"service_version": "3.4.0",    
"user_id": "test_user"
}

• Try to extend the reservation (/api/v2/reservations/extend) using the reservation_id obtained in the previous step and in the attached_consumers.consumer_id field, put another consumer than used to get the license

{  
"reservation_id": "{{reservation_id}}",  
"service_version": "3.4.0",  
"user_id": "test_user",  
"consumer_id": "mcu_qpe",  
"attached_consumers": [    
     {      
      "consumer_id": "mcu_qpe",      
      "consumer_version": "8.0.0",      
      "consumer_features": {        
         "feature_key": "android, qt, ios, java, mac, tk, vnc, web, windows"      },      
      "consumer_build_timestamp": "2024-12-12"    }  
  ]
} 

• Get the reservation again for the same user (same payload as in the first step) - check the reservation_id

Actual:

After sending the request to extend the license, I got a 400 error and error code 4100016. After making the same request again, the code changed to  4100011. The user's reservation_id was regenerated. I attached also video, if the steps are not clear enough. 

Expected: If the request fails due to a bad request, it should not cause the reservation_id regeneration.