Much smaller aircraft, which could make a difference.
The lockheed electra is a smaller aircraft, but people have been looking for that one a lot longer, too.
Lady be Good, a B-24 in WWII did this. Flew by its base at night and crashed in the Libyan desert. Wasn’t found until 1958.
A French attempt just before Lindberg’s flight simply vanished.
Steve Fossett vanished in Nevada for months despite a furious, professional, well-funded and immense search effort.
Flight 19 5 bombers vanished off Florida.
The ocean is very very big. Its entirely possible this machine went deep out over the southern part of the Indian Ocean, ran out of fuel, crashed and sank. We simply may never know what happened.