WDMycloud and Panasonic TV set

I have a 2015 WDMyCloud 2TB and I’ve just got a Panasonic TV TX-55GZ1000E.
With the old TV set (a Samsung one) everything was Ok.
With the new one, I see the WD NAS, with all the files, but a lot of them are marked with “file not supported”.
I’ve not found any reason for that: they are mp4 files, both FHD and UHD, like the good ones, with transfer rates very similar.
More: if I reprocess the files with my video editing programs, producing the same mp4 files, they are ok!
Does anybody experience anything similar?
A question: the playing software is located in the TV set, as I suppose?
P.S.: the very same files that are not supported with WDMycloud, on a USB device, are very well played by the TV!
Thanks in advance for every suggestion.

Hi,

You could refer to the following link: https://support-en.wd.com/app/answers/detail/a_id/14347