Hi, @mickee.
I've found the following older (March 2021) related topic here in the Ubuntu MATE Community:
In that "Caja device Names" topic, the accepted answer (Solution) is the following one by @Marcel_Karnat :
So, I suggest that, in GParted (GNOME Partition Editor), you right click on each one of those two ext4 filesystems (that belong to USB disks), then choose the "Label File System" option from the context menu and then write a label for each of them (it's possible that you have to unmount them first).
In a related note, you can see the names and labels of your devices using a command such as the following command (which is intentionally excluding the "loop" devices from the output):
lsblk -o name,size,label,type,mountpoints | grep --invert-match 'loop'