I run KDE Neon on 2 systems. I have multiple issues, and there seems to be no way to diagnose them.
On system "A" whenever you plug in any USB device Xorg consumes about 95% CPU and makes the system unresponsive for about 5mins.
On system "B" sometimes when you wake from sleep the system thinks the alt key is stuck down and won't let you interact with the GUI.
On system "A" the rendered backend reverts back to XRender.
On system "A" and system "B", the invert mouse scroll setting isn't applied after boot.

My question is how would one go about diagnosing these issues?

USB-Problem:

1.
journalctl -b --follow --full --output=verbose
2.
Plug USB-stick in, and see if You get any helpful message.

@NoNameNoBlame thanks for providing some help


Running: journalctl -b --follow --full --output=verbose
and plugging in a keyboard shows:

Code: Select all

    _SOURCE_REALTIME_TIMESTAMP=1559602692129689
Mon 2019-06-03 23:58:12.131574 BST [s=7bfb0680fc9c4ce8b0f03bc7fb2400e3;i=cf0c;b=0e2d8b01a9b24608b9d94ed704441272;m=7ebfa2cd0;t=58a734c748b1f;x=b5446380c3d6a1bb]
    _MACHINE_ID=eeda0dc82cfb4d6c8ee83f4002b69cb5
    _HOSTNAME=saturn
    PRIORITY=4
    _UID=0
    _GID=0
    _SELINUX_CONTEXT=unconfined
    _SYSTEMD_SLICE=system.slice
    _TRANSPORT=journal
    _CAP_EFFECTIVE=3fffffffff
    GLIB_OLD_LOG_API=1
    _PID=2026
    GLIB_DOMAIN=UPower-Linux
    _COMM=upowerd
    _EXE=/usr/lib/upower/upowerd
    _CMDLINE=/usr/lib/upower/upowerd
    _SYSTEMD_CGROUP=/system.slice/upower.service
    _SYSTEMD_UNIT=upower.service
    _BOOT_ID=0e2d8b01a9b24608b9d94ed704441272
    _SYSTEMD_INVOCATION_ID=4599596fa5224e65bd7151d17168328d
    MESSAGE=unhandled action 'bind' on /sys/devices/pci0000:00/0000:00:14.0/usb3/3-9/3-9.4/3-9.4.2
    _SOURCE_REALTIME_TIMESTAMP=1559602692131574

Anything there that looks scary? What do people advise?