Sharing folder changes folder to lowercase

Thanks for the post. Unfortunately, that behavior is expected sometimes, and there isn't a way to just prevent it. The original casing isn't always available for all components. There's a note about this in the API v2 documentation, under "Case insensitivity":

Also, while Dropbox is case-insensitive, it makes efforts to be case-preserving. Metadata.name will contain the correct case. Metadata.path_display usually will contain the correct case, but sometimes only in the last path component. If your app needs the correct case for all path components, it can get it from the Metadata.name or last path component of each relevant Metadata.path_display entry.

(That's referring to the Metadata objects in particular, but it applies anywhere file metadata, e.g., paths, are used.)

We understand this is non-ideal of course, and I'll forward this on to the team as feedback, but I can't make any promises as to if or when this might be improved in the future.