Thumb drives don't hotplug on Debian 10

[appealsman]

Self-explanatory. Since installing Debian 10, thumb drives do not hotplug and are not detected and do not show up on device notifier. No reference to them in fstab. Udev is installed. GVFS is installed.

How do I diagnose and fix?

[stevepusser]

Removable drives get mounted in /media now, and fstab is out of the picture.

Are you running the default GNOME desktop?

[appealsman]

I am running KDE.

[appealsman]

Ran DMESG -w and got this-

ofile_load" profile="unconfined" name="/usr/sbin/mysqld-akonadi///usr/sbin/mysqld" pid=
490 comm="apparmor_parser"
[   68.631159] audit: type=1400 audit(1593473330.533:11): apparmor="STATUS" operation="p
rofile_load" profile="unconfined" name="libreoffice-senddoc" pid=496 comm="apparmor_pars
er"
[   68.880434] Adding 9227464k swap on /dev/sda3.  Priority:-2 extents:1 across:9227464k
FS
[   70.818178] Bluetooth: BNEP (Ethernet Emulation) ver 1.3
[   70.818181] Bluetooth: BNEP filters: protocol multicast
[   70.818187] Bluetooth: BNEP socket layer initialized
[   72.971909] IPv6: ADDRCONF(NETDEV_UP): enp5s0: link is not ready
[   72.973201] IPv6: ADDRCONF(NETDEV_UP): enp5s0: link is not ready
[   72.974008] alx 0000:05:00.0 enp5s0: NIC Up: 100 Mbps Full
[   72.974221] IPv6: ADDRCONF(NETDEV_CHANGE): enp5s0: link becomes ready
[   76.266217] usblp0: removed
[   76.272561] usblp 1-4:1.0: usblp0: USB Bidirectional printer dev 3 if 0 alt 0 proto 2
vid 0x04F9 pid 0x0045
[   86.400111] usb 2-1.1.1: Failed to suspend device, error -110
[  134.742954] xhci_hcd 0000:03:00.0: WARNING: Host System Error
[  134.742977] xhci_hcd 0000:03:00.0: Event logged [IO_PAGE_FAULT domain=0x0000 address=
0x00000000fff96000 flags=0x0000]                                                         
[  134.759079] xhci_hcd 0000:03:00.0: Host halt failed, -110
[  140.980039] xhci_hcd 0000:03:00.0: xHCI host not responding to stop endpoint command.
[  140.996101] xhci_hcd 0000:03:00.0: Host halt failed, -110
[  140.996103] xhci_hcd 0000:03:00.0: xHCI host controller not responding, assume dead
[  140.996126] xhci_hcd 0000:03:00.0: HC died; cleaning up
[  140.996168] usb 5-1: USB disconnect, device number 2
[  140.996172] usb 5-1.3: USB disconnect, device number 3

[appealsman]

Solved, sort of.

The system decided that it didn't like an external USB hard drive that was connected. Once I removed it, everything began functioning once again.