I've found the FAA's map to frequently be inaccurate. It doesn't, for example, show the temporary no-fly zone in place at the Dakota Access pipeline site in North Dakota.
In my admittedly limited experience, AirMap is better.
I use airmap too, both the phone app and their web based version. Only negative I have is that the phone app doesn't rotate (vertical position only) and it appears to still be using the old 333 exemption guidelines. When you click on 'commercial' it shows a 3 mile radius around airports - removed under the new Part 107 operations.