Stray TCAS targets

[CFE12]

Evening,

RJ100 in MSFS2024 SU3.

The last week or so I've noticed unexplained targets on TCAS. I normally fly on VATSIM with AI traffic turned off and they do not correspond with aircraft connected to the network.

I checked my settings and I had:

• AI aircraft set to off in Graphics settings, and
• AI traffic selected on in the Live settings window so as to display live sea traffic.

I wondered if this was injecting "invisible" live traffic into the sim so this evening I selected Live traffic to off too but I still seem to be getting stray targets. This photo was with all traffic selected off and having disconnected from VATSIM (I had been connected):

I am not using any other software to inject traffic.