During a Chinese class, a student pronounced 复杂 as fu3za2, instead of the official pronunciation fu4za2. The Chinese teacher corrected the student but then mentioned many native speakers pronounce it as fu3za2 as well, particularly in the south or something like that.
Have any of you heard this different pronunciation and perhaps know the reasons behind why such a tonal difference exists? Is it, like the teacher said, just simply a case of south Chinese pronunciation? Or is it more complex than that?