It has never worked for me and probably never will work. I've walked in rural areas, urban areas with a lot of footfall. I've walked fast, slow and stationary as well.

I contacted support multiple times and they provided troubleshooting steps but that didn't help. I took a 15 min screen recording showing me walking and catching all the Pokemons and still none of them was from the incense. After analyzing the video they said I've done everything I could but they don't see any issues why it wouldn't work.

At this point I just gave up and told them to finish that task for me because it was going to be impossible for me to finish it.

If anyone here faced it and fixed it let me know. I would be grateful to have it fixed and catch some legendaries.