No warning on transmitter

[falicityman_7]

Yesterday on 9-11 I was at the Detroit River to launch my Mavic Air 2 I was at the waterfront park by the bridge to Canada flying to take pictures,
when a Black Helicopter was flying above, there was no warning on my screen ! has anyone had the same thing happen to them ?
usually on the upper left hand corner there would be a orange warning box manned aircraft ! with a voice I found this strange !!!
Faciliy7

 

[itsneedtokno]

Not every aircraft has ADS-B. Helicopters typically fly lower and can appear unexpectedly.