When making a backup, sometimes Synk encounters files on a destination that don’t have a counterpart in the source.
Synk keeps a catalog of the files that it’s aware of and has seen in the source, and by default, if it had previously seen an extra file in the source, it assumes that it was deleted in the source and propagates that by deleting the copy in the destination.
In Synk Pro, the Advanced settings area for a script contains an “Extra files in destination” option. You can use this setting to change the behavior to ignore any extra files and leave them in place in the destination, or to always delete any extra files found on the destination regardless of whether they’ve previously been seen in the source.