Two Raspberry => soft copy with Backup/home file ??

[Nachteule]

You have a filesystem problem

So first question, tell me the occupied size of your source /home volume

Code:

sudo du -sxh /home

Second, do you have enough disk space free on target?

Code:

sudo df -h /

I suppose you have a filesystem problem on target. Either it is damaged and has to be fixed, or another simple reason is, while extracting the home image it runs out of disk space