Why do full backups using the HA Google Drive Backup show different sizes

Love this backup addon. Full backups on my Google Drive and Synology DSM.

I notice that my full backup sizes fluctuate. Posted are the two most recent, quite a difference in size. What would cause this assuming I’ve made no big changes to my setup


?

Maybe this:

Have you restarted HA. past 2-3 days ? , logfiles get flushed, maybe you had some (Huge) logfiles 3 days ago

That must be it. Thank you.