Backup create empty entry (filename=".") in mdl_files table

Hi everyone,

I noticed that when I create a course backup Moodle seems to populate the files table with the backup record (xyz.mbz) and another empty record with filename set to "." - see picture below. Those "." files are created on the disk but are empty.

Does anyone know why Moodle create those empty files? Can I delete them?

Thank you in advance for your help

Moodle 3.8.1+ (Build: 20200214)
CenOS 7.5
PHP 7.4.3
MySQL  Ver 15.1 Distrib 10.1.41-MariaDB