The reason for listings being assigned with the same P24 ID is because the listings have the same images.
According to P24 "listings need to have unique images for each property. You may not use the same or similar images for multiple listings"
Here is an example of listings that have been assigned with the same P24 ID due to the same images being used.
First listing - same images indicated below:
Second listing - same images indicated below:
To resolve the issue, delete the same images from either listing. Once done, please contact Support and we will escalate to our developers to unlink the P24 ID.
Note: For developments - if unique images are not possible for all units, create one listing and include the different units available in the property description.