Post your log, easily done from the command line (assuming the system has internet access): cat /var/log/Xorg.0.log | nc termbin.com 9999
Post the resulting URL here.
45.739] (II) config/udev: Adding input device Logitech USB Receiver Mouse (/dev/input/event8)
[ 45.739] (**) Logitech USB Receiver Mouse: Applying InputClass "libinput pointer catchall"
[ 45.739] (II) Using input driver 'libinput' for 'Logitech USB Receiver Mouse'
[ 45.739] (**) Logitech USB Receiver Mouse: always reports core events
[ 45.739] (**) Option "Device" "/dev/input/event8"
[ 45.740] (II) event8 - Logitech USB Receiver Mouse: is tagged by udev as: Mouse
[ 45.741] (II) event8 - Logitech USB Receiver Mouse: device is a pointer
[ 45.742] (II) event8 - Logitech USB Receiver Mouse: device removed
[ 45.743] (II) libinput: Logitech USB Receiver Mouse: Step value 0 was provided, libinput Fallback acceleration function is used.
[ 45.743] (II) libinput: Logitech USB Receiver Mouse: Step value 0 was provided, libinput Fallback acceleration function is used.
[ 45.743] (II) libinput: Logitech USB Receiver Mouse: Step value 0 was provided, libinput Fallback acceleration function is used.
[ 45.743] (**) Option "config_info" "udev:/dev/input/event8"
[ 45.743] (II) XINPUT: Adding extended input device "Logitech USB Receiver Mouse" (type: MOUSE, id 14)
[ 45.743] (**) Option "AccelerationScheme" "none"
[ 45.743] (**) Logitech USB Receiver Mouse: (accel) selected scheme none/0
[ 45.743] (**) Logitech USB Receiver Mouse: (accel) acceleration factor: 2.000
[ 45.743] (**) Logitech USB Receiver Mouse: (accel) acceleration threshold: 4
[ 45.744] (II) event8 - Logitech USB Receiver Mouse: is tagged by udev as: Mouse
[ 45.745] (II) event8 - Logitech USB Receiver Mouse: device is a pointer
[ 45.746] (II) config/udev: Adding input device Logitech USB Receiver Consumer Control (/dev/input/event9)
[ 45.746] (**) Logitech USB Receiver Consumer Control: Applying InputClass "Evdev keyboard"
[ 45.746] (**) Logitech USB Receiver Consumer Control: Applying InputClass "libinput keyboard catchall"
[ 45.746] (II) Using input driver 'libinput' for 'Logitech USB Receiver Consumer Control'
[ 45.746] (**) Logitech USB Receiver Consumer Control: always reports core events
[ 45.746] (**) Option "Device" "/dev/input/event9"
[ 45.747] (II) event9 - Logitech USB Receiver Consumer Control: is tagged by udev as: Keyboard
[ 45.748] (II) event9 - Logitech USB Receiver Consumer Control: device is a keyboard
[ 45.749] (II) event9 - Logitech USB Receiver Consumer Control: device removed
[ 45.750] (**) Option "config_info" "udev:/dev/input/event9"
[ 45.750] (II) XINPUT: Adding extended input device "Logitech USB Receiver Consumer Control" (type: KEYBOARD, id 15)
[ 45.750] (**) Option "xkb_rules" "evdev"
[ 45.751] (II) event9 - Logitech USB Receiver Consumer Control: is tagged by udev as: Keyboard
[ 45.751] (II) event9 - Logitech USB Receiver Consumer Control: device is a keyboard
[ 46.145] (--) NVIDIA(GPU-0): DFP-0: disconnected
[ 46.145] (--) NVIDIA(GPU-0): DFP-0: Internal TMDS
[ 46.145] (--) NVIDIA(GPU-0): DFP-0: 165.0 MHz maximum pixel clock
[ 46.145] (--) NVIDIA(GPU-0):
[ 46.190] (--) NVIDIA(GPU-0): LG Electronics LG ULTRAGEAR (DFP-1): connected
[ 46.190] (--) NVIDIA(GPU-0): LG Electronics LG ULTRAGEAR (DFP-1): Internal TMDS
[ 46.190] (--) NVIDIA(GPU-0): LG Electronics LG ULTRAGEAR (DFP-1): 600.0 MHz maximum pixel clock
[ 46.190] (--) NVIDIA(GPU-0):
[ 46.191] (--) NVIDIA(GPU-0): DFP-0: disconnected
[ 46.191] (--) NVIDIA(GPU-0): DFP-0: Internal TMDS
[ 46.191] (--) NVIDIA(GPU-0): DFP-0: 165.0 MHz maximum pixel clock
[ 46.191] (--) NVIDIA(GPU-0):
[ 46.236] (--) NVIDIA(GPU-0): LG Electronics LG ULTRAGEAR (DFP-1): connected
[ 46.236] (--) NVIDIA(GPU-0): LG Electronics LG ULTRAGEAR (DFP-1): Internal TMDS
[ 46.236] (--) NVIDIA(GPU-0): LG Electronics LG ULTRAGEAR (DFP-1): 600.0 MHz maximum pixel clock
[ 46.236] (--) NVIDIA(GPU-0):
[ 46.238] (--) NVIDIA(GPU-0): DFP-0: disconnected
[ 46.238] (--) NVIDIA(GPU-0): DFP-0: Internal TMDS
[ 46.238] (--) NVIDIA(GPU-0): DFP-0: 165.0 MHz maximum pixel clock
[ 46.238] (--) NVIDIA(GPU-0):
[ 46.282] (--) NVIDIA(GPU-0): LG Electronics LG ULTRAGEAR (DFP-1): connected
[ 46.282] (--) NVIDIA(GPU-0): LG Electronics LG ULTRAGEAR (DFP-1): Internal TMDS
[ 46.282] (--) NVIDIA(GPU-0): LG Electronics LG ULTRAGEAR (DFP-1): 600.0 MHz maximum pixel clock
[ 46.282] (--) NVIDIA(GPU-0):
[ 46.284] (II) NVIDIA(0): Setting mode "HDMI-0: 2560x1440_120 @2560x1440 +0+0 {ViewPortIn=2560x1440, ViewPortOut=2560x1440+0+0}"
[ 46.797] (--) NVIDIA(GPU-0): DFP-0: disconnected
[ 46.797] (--) NVIDIA(GPU-0): DFP-0: Internal TMDS
[ 46.797] (--) NVIDIA(GPU-0): DFP-0: 165.0 MHz maximum pixel clock
[ 46.797] (--) NVIDIA(GPU-0):
[ 46.842] (--) NVIDIA(GPU-0): LG Electronics LG ULTRAGEAR (DFP-1): connected
[ 46.842] (--) NVIDIA(GPU-0): LG Electronics LG ULTRAGEAR (DFP-1): Internal TMDS
[ 46.842] (--) NVIDIA(GPU-0): LG Electronics LG ULTRAGEAR (DFP-1): 600.0 MHz maximum pixel clock
[ 46.842] (--) NVIDIA(GPU-0):