Snapshot's snapshots fail on /uploads folder

Snapshot full backup (Snapshot -> Snapshots) fails on uploads folder. Specifically, it fails on the /wp-content/uploads/2017/10 folder. Excluding it, let's snapshot continue, but then it goes through the rest of "uploads" folder and breaks after a long while on "plugins".

During the process also resources are maxed out (even slowing down other sites on the same server).