Have a look at the results from when that example was created (they are on our homepage).
You’ll see that the second apartment (the one in the middle to the west) only has one supermarket, and if you zoom in its on
Judah Street between
44th Av. and
If you compare your results (actually, if I compare mine that have run just now), you’ll see that your isochrone actually ends before that - somewhere on
43rd Av. between
Judah Street and
The POI-search therefore doesn’t find this supermarket, which should be reflected in the output of POIs around apartments - the second apartment should list 0 supermarkets.
It doesn’t add any duration for routing to that supermarket, and
cat['durations'] is an empty sequence for the supermarket category and the second example.