IP addresses are showing "used" status but in reality its not !

[#1]

Hi everyone,

Im running a discovery on a /24 subnet and it is reverting "used" status for all of the IP addresses inside the subnet. In reality, most of the IP addresses are actually not alive in the subent but they returned "used" status. if I try to open one of the ip addresses which stating "used" to see its details, it shows bothing except the discovery date, which is weird ! Also, to verify, I try to ping using "ping now" , it confirms that the IP is not alive ... 

Is this some sort of a bug ?

[#2]

Is their any host or DNS record assiciated to these ip's in ipam or did you make a reservation?

if you clear that information from the database it should remain unised

[#3]

nope, no DNS recorsd are assoicate - no dns service is running. 
no fixed addresses or reservation is done.

strangely enough ... after a day I noticed the non-alive addreses are cleared and became unused ! 

so, I need to understand how they were discovvered as "used" in the few hours when I added them becuase this was so confusing.