Have been running Backup and Migrate on my Drupal projects for some time now (since Drupal 7.x), and have never come across this issue before: when backing up the database, even when compression GZip is selected, the database will export with no compression. This happens when using Quick Backup or Advanced Backup. Have been checking the logs, see no anomalies, and all other site functions appear to be fine. As a sanity check, tried toggling compression settings, but it didn't seem to resolve anything.
Module version: 5.0.3
Drupal core version: 9.5.3
PHP version: 8.0
Active
5.0
Code
The change is currently missing an automated test that fails when run with the original code, and succeeds when the bug has been fixed.
Thank you for reporting the problem.
How are you confirming this - via filenames in the list of backups, or by examining the files in the destination directory?
By examining files in the destination directory. It's also pretty apparent by the file size, itself.
Let's add test coverage to make sure the backup files work as expected.