ADSB In/Out traffic question

[Flying_Monkey]

I've got a KT74 for ADSB Out in my Cherokee and a Stratus 2s for ADSB In connected to a yoke mounted iPad mini. I was flying yesterday at 8500 feet and saw a traffic target indicated 1500 feet below me and converging from my 11 oclock. ATC advised me of the traffic and soon after the traffic disappeared from my display I checked and Foreflight indicated I was connected to multiple ADSB towers. However, ATC continued to advise me of the aircraft's position.

I was under the impression that with ADSB out, I would receive the same traffic picture as ATC. How come ATC could still see this guy and I couldn't?

 

[GM.]

 

[Flying_Monkey]

 

[piperfan]

 

[sanjiv]

 

[Flying_Monkey]

 

[Raptor05121]

 

[EchoDelta]

 

[msires]

 

[sanjiv]