A few new infos from a kate user:
I can make a BACKUP and a RESTORE without errors when I don't flash another ROM between these two actions.
If I flash an other ROM between BACKUP and make a RESTORE, then I get these errors in the log:
I:Restore filename is: /sdcard1/WOLF/.ZALOHY/c3a5ad47/2017-11-16--20-47-15_lineage_kenzo-userdebug_7.1.2_NJH47F_65e0a2/
E:Unable to find file system (first period).
E:Unknown restore method for '/splash'
I:Set page: 'restore_action_complete'
I
peration_end - status=1
After that, the BACKUP is stopped with error...but it boots up ok. So it is more cosmetic?