I am an end user, not a developer. I have a 2019 MacBook Pro 16" 1 TB SSD running Monterey 12.3 Beta. I got it from a reseller and it's my first Mac so I don't know much about anything. Just trying to learn about Macs after 40 years with Windows. Time Machine is set up with an external 4 TB Seagate drive. Set up for encryption and automatic backups. It has completed a few back ups for about 288 GB but says a full back up would be 980 GB. Periodically I get an error message that says a back up can't be completed because a snapshot of the disk couldn't be created. Or it will say there's not enough space on the Time Machine drive, which makes no sense since it's so much larger. l've reformatted the Ext HD and started over but it's still not working right. Ideas?