Time Machine backup fails immediately on new Mac mini
Time Machine issue: I recently obtained a new Mac Mini with a 1TB SSD, for Time Machine backups I also obtained a new 2TB external hard drive. After formatting the drive and adding it to Time Machine I started the backup. The 'Preparing to back up' status was displayed and then within 2 seconds there was a pop up with the message 'Backup not completed, Time Machine couldn't back up to TMBackup (my drive)'. There is a details button but pressing it just closes the pop up.
I should add that I've used Time Machine for years, also I used Migration Assistant to move my data with the input being the Time Machine backup from my previous system.
Mac mini, macOS 26.2
