find() doesn't work for some sub-directories & upload() doesn't upload to dict

[njikgg]

I've tried using methods from examples on pypi and GitHub:

folder = m.find('my_mega_folder')
m.upload('myfile.doc', folder[0])

However, sometimes find(folder) returns a NoneType instead of a list (for example, in folder1/folder2/folder3 tree only find(folder1) & find(folder1/folder2) are returned as lists, but find(folder1/folder2/folder3) is returned as 'None').

I would have tried move() but I'm not really sure how to use it and reading the source code only led me to figuring out that I need a target ID, which is basically find(folder).