When USB device is busy Nautilus must show if a loop device is mounted in USB disk because is very difficult for a normal user guest why can not umount USB disk.
lsof didn’t show any file open in USB disk.
Thanks to DeepSeek I discovered who was using a file in USB device.
I did these steps to umount USB disk:
$ losetup -a
/dev/loop1: : (/run/media/oscar/2-Ventoy/FreeBSD-13.2-RELEASE-amd64-memstick.img)
$ sudo lsblk -f /dev/loop1
NAME FSTYPE FSVER LABEL UUID FSAVAIL FSUSE% MOUNTPOINTS
loop1
├─loop1p1 vfat FAT32 EFISYS 43DB-0D0B
├─loop1p2
└─loop1p5 ufs 2 FreeBSD_Install 642faa454e7df8b5
$ sudo losetup -d /dev/loop1p5 $ losetup -a
$
$ nautilus --version
** Message: 08:08:02.768: Connecting to org.freedesktop.Tracker3.Miner.Files
GNOME nautilus 49.3
$
I attached image with window that does not show loop mounted on USB disk file.
