Backup incomplete - one folder and its subolders excluded from created backup

Hello

After doing full website backup with shared hosting Cpanel backup feature,
I've noticed that one folder in public_html/components/component_name/uploads
was completely excluded from created backup.
That folder had 900 subfolders with 5-30 images each, approx 700 mb size.

I tried several times and every time same folder would be excluded.
Folder had same permissions like any other folders.
It's located on Amazon servers
I didn't configured that server.

Questions:

- What could be the reason for that backup excluding that particular folder?
- is it maybe because of ownership? (I cannot check that anymore)
- does Cpanel default backup function creates some logs where i could see possible errors?
- is yes, where is it?

Note it's standard Cpanel on shared hosting so i don't have special access there.

Although I managed to move these excluded files manually with cpanel file manager
I still wonder if some other folder(s) might be missing too.

cPanel Version 11.46.2 (build 0)
Theme x3
Apache Version 2.2.29
PHP Version 5.4.36
MySQL Version 5.5.42
Architecture x86_64
Operating System linux

Thanks,
Regards