Nmap Tracker Integration does not create Devices

My namp tracker finds 52 entities, but only 13 devices on the network:

I expect devices and entities to go hand in hand (every device on the network is as device in nmap and an entity).

Has anybody similar observations? Do I have a configuration problem?

Any hint welcome!

A devices can easily have multiple entities.
How a device is defined is up to the integration.
Here it could be based on IP addresses and the numbers indicate that there might be 4 entities per device if they are evenly distributed, which is not a certainty though.

Devices is really not something you use much in HA. It is mostly entities you will be working with.