Immages Date On Mi4c

Oct 28, 2016
I hold a new Mi4c from few days, and it cames to me with a MIUI 8.1 by 6.8.25 dev
Generally It's all fine, only when I try to copy my backupped files on internal memory the date of last modify is changed from the original to the date at moment of the copy. This is boring because the immages cannot be filtered by date in the gallery.
I've tried several metods, from windows, from ubuntu graphical and terminal, via ftp, zipped file copyed and unzipped directly fom the phone. Always same result.
Now I'm thinking can be a rom issue, someone has any suggestion?