Time Machine backup repeatedly "delayed."

I have exactly the same issue. I have two 4 TB SSDs that I use as backups. I swap them out one a week, keeping one a remote location and using the other for backups. Since Sonoma, the message is posted "Backup delayed" and corresponds the drive that is in storage. The TM does not acknowledge the new drive, to which is appears to be sucessfully saving backups.

I have never had this problem before when using new MacOS. Please address ASAP.

This is definitely a Sonoma issue. I have another Mac on Ventura backing up to the same drives, and that is working flawlessly.

I am not sure how to get this to Apple for remedy.

Me too. I never had this issue until I upgraded my M1 Max 4TB MacBook Pro to Sonoma 14.1. Even if I restart the backup, it just keeps reporting "Backup Delayed."

Is the computer running off of Battery Power ?

I know for a fact using another Method to make a Backup off of Battery Power and the CCC Application will Alert me of this fact >> Battery Power

This is a good thing as it may avoid the computer from >>

1 - Running out of Battery Power when performing this backup.

2 - Worse still, getting 50 % done on the Backups and loosing power

In point 2 above, not only does the computer shutdown but all may Corrupt the TM Backup Drive

Corrupted Time Machine Backup Drive could cause ALL TM Snap Shoots to be Corrupted and therefore lost forever

PS: Bigger thread on all this at https://discussions.apple.com/thread/255171911

Welcome

Perhaps some info from this external Safe Link will help

https://osxdaily.com/2010/02/25/time-machine-backup-delayed/

Adding the chorus - problem started after 12/20 - the last successful TM backup completed. Updated to 14.2.1. No joy.