Cannot create new folder on a new drive
This is not a question but more about putting a Time-Machine backup on a new drive.
After initialising a new drive, I elected to accept the option to make it a Time-Machine backup, after which I cannot create new folders.
My solution was to erase the disk and not to backup Time Machine on it.
Alternatively, put a Time Machine in another partition.
iMac 27″, macOS 15.0