Document upload doesn't work with Greek file name!

I am using sc Version 9.9.013 (8)
I am facing a very big problem, and i really don’t know why this happens.
Basically all i want to do is upload files named in Greek characters to the tmp folder.
I am using a simple control form, and the application settings are Unicode UTF-8 - language Greek
Let’s say we have 1 file, named like this: ελλαδα123.png

  1. It’s working fine in the development server. (Localhost)

  2. But in the production server works ONLY IF THE FILE NAME BEGINS WITH AN “ENGLISH” CHARACTER, even if the following characters are in Greek.
    For example: Uελλαδα123.png

Otherwise if the file doesn’t start with an english character and you upload the file in the production server like this: ελλαδα123.png the file is uploaded like this: ?????123.png

Inside the database (mysql) the Document name is stored correctly no matter if it is in production env or in development…no matter the file is named like this: ελλαδα123.png or ελλαδα123.png
So I know the problem is somewhere in the upload part with the encoding maybe ?

Can anyone help me solve this ? I can’t tell my clients to rename their files from Greek to English for obvious reasons.
I will do some tests, and i will look this very deep.
I will return with the feedback.

I also found this topic from 2013 that is exaclty the same with me, the guy wants to name his file in japanese characters. The answer is still unknown

V7 : Upload don’t work with Japanese file name !