Time Machine fails verification and keeps creating new backups

The other possibility is network issues.

And when I say that I mean of course wireless issues in 99% of cases. Ethernet is reliable.

If you are using wireless do make sure you have good speed to the backup device. How long does it take you to do a full backup to either TC or Synology when you have tried? How many GB is that backup?

Personally though I agree with needing to use 3rd party backup. I use Carbon Copy Cloner. It has worked very solidly once setup. It has decent logging so you can easily see if a backup worked. It does work better to a local USB drive as Time Machine also does. In the case of CCC it is creating a bootable clone. That is extremely useful as you can immediately test if a backup is viable by simply booting from it.

There are a number of other Mac backup software but IMHO is best value. (I pay for license like everyone else.. no sponsorship) Several of us here use it and recommend it for people to use in place of Time Machine. I run both.. in order to keep track of and help with Time Machine queries. However I realised a few years back the continual

which happened on a regular basis.. grew tiring. With CCC now as the main backup.. TM can delete itself at regular intervals and I just click "Start New Backup" and ignore the rest.

Frankly.....in my opinion.....Time Machine has not been all that reliable backing up to a network drive since the Sierra operating system was introduced. The issues worsened in High Sierra and continued with Mojave.

Things are much more reliable when Time Machine backs up to a drive that is connected directly to the Mac......like a USB drive for example.

There is not really much that you can do, since Time Machine is software built into the Mac operating system.

One thing that you might try.......if you have not already done so.......would be to check the hard drive on your Mac for errors. If you decide to do this.......

Open Disk Utility on your Mac (Finder > Applications > Utilities > Disk Utility)

On the left panel of the window, click to select your Mac's hard drive named Macintosh HD, unless you have changed the name

Click First Aid near the top of the window

The process might take 5-20 minutes or longer depending on how much data is stored on the Mac's hard drive

Completely erase/format the drive that you are using for Time Machine again and try another backup

Good luck!

I also use Carbon Copy Cloner to back up to a Time Capsule, as well as to a USB drive that is connected directly to the Macs. No problems at all backing up to either a "network" drive or a "local" drive.

At the same time, I see the dreaded Time Machine message that LaPastenague has posted all too often. It's kind of cruel joke.......mentioning that Time Machine has "verified" my backups and they are now useless. Sometimes, I can go 3-4 months before it appears, and sometimes it might only be a few weeks. The point is, I know it will appear.....I just don't know when.