Time Machine bugs; can't backup reliabily since Monterey

Boot into Safe Mode according to Start up your Mac in safe mode - Apple Support and try running Time Machine from there to see if the problem persists. Reboot normally and test again.

NOTE: Safe Mode boot can take up to 3 - 5 minutes as it's doing the following; 

• Verifies your startup disk and attempts to repair directory issues, if needed

• Loads only required kernel extensions (prevents 3rd party kernel/extensions from loading)

• Prevents Startup Items and Login Items from opening automatically

• Disables user-installed fonts 

• Deletes font caches, kernel cache, and other system cache files

I have the same problem with my brand new 16-inch MacBook Pro and Mac OS Monterey.

What I tried:

• boot in safe mode (as suggested previously)
• formatting then fresh set up of my external Synology NAS which was the destination of all previous backups
• back up using wired / wireless connection

Unfortunately nothing helped: the backup is always running just fine, completes to 100%, then clean up and then I still see: Latest backup - None; Oldest backup - None.

Hopefully this problem will attract some attention from Apple.

Thanks!

Have you installed or run any "cleaning", "optimizing", "speed-up", anti-virus or VPN apps on your Mac? Users who were having the same problem that had Sophos A/V installed fixed the problem by uninstalling Sophos completely with the developer's instructions.

Yes, and to make things even worse, it takes up all the space of the drive, but the files themselves are invisible. I've had to manually mount the external drive using the terminal to so much as see anything.

Monteray is broken and you'd think they'd have tested this. Backing up is a pretty important thing and before now it's been easy.

I'm having the same problem, brand new m1 Pro Macbook Pro won't complete initial Time Machine Backup. I've tried two brand new SDDs, both formatted to APFS. I only have 200GB of data, but the initial backup takes about 30 hours to reach 70% and then crashes.

I now have a support ticket open with Apple. The ticket has been escalated from a first level person to a second level person, but neither have been able to fix the problem, nor do they seem to know about this issue. I'll post an update if we discover a resolution.

This started for me when I updated my 2020 MB Air M1 to Big Sur 11.6.1 from 11.6. Backups were slow but functional to my Synology NAS prior to that, now they won't complete after that update.