Auto backup with older video files not saved

Hi, I have an issue with the auto backup of the videos files from an iphone, at the end of the backup process, only about 10 newer video files are saved aside from the remaining 500 video files. I’ve left the phone unlocked during the whole process.

How do I fix this?
My devices used are My cloud home 6tb
Iphone with latest ios11 installed .

Hello,

Are the other 500 videos on iCloud or on the Physical iPhone?
Are the other 500 videos located in the iOS Camera Roll or within files?