Sonoma - file always copying instead of moving

On one of my connected disks, if I drag and drop any file, from for example the root, into a folder, it will copy, leaving the original on the root and depositing a copy in the folder. This should be the normal operation if I pressed cmd while dragging. but its happening all the time.

This does not happen on the desktop, any location on the internal SSD or other connected disks, only on one specific disk. Im sure this is new behavior but I cnnot in all honesty link it to upgrading to Sonoma, as this disk has not been connected for a while.

Mac book Pro

2,6 GHz 6-Core Intel Core i7

AMD Radeon Pro 5500M 8 GB

Intel UHD Graphics 630 1536 MB

32 GB 2667 MHz DDR4