A callsign appearing in the cluster for no reason.

[SP4OLI]

Hello friends! Why do I often see operators in the cluster window who aren't listed but are only using Log4OM? I see this many times throughout the day. For example, my friend has the Log4OM program, and when he turns it on, I see him appear in the cluster every few minutes, but the reporter window remains empty. None of them are transmitting on the given frequency. It's enough for them to be on the amateur radio band for a moment.

[G4POP]

Do you have the supercluster running?

[SP4OLI]

YES, but I have the same problem when it is on and off.