Hello. For some time I having this issue of random disconnect of USB devices (keyboard, mouse). One PC disconnects mouse after boot (only partially - scrolling is still working) - disconnecting and reconnecting USB mostly repair this. Other PC (notebook) have connected new keyboard and mouse which randomly disconnects like this:
čec 15 08:58:23 adam-tuxedo mtp-probe[2746]: bus: 1, device: 41 was not an MTP device
čec 15 08:58:23 adam-tuxedo mtp-probe[2746]: checking bus 1, device 41: "/sys/devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2.2"
čec 15 08:58:23 adam-tuxedo mtp-probe[2745]: bus: 1, device: 40 was not an MTP device
čec 15 08:58:23 adam-tuxedo mtp-probe[2745]: checking bus 1, device 40: "/sys/devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2.1"
čec 15 08:58:23 adam-tuxedo systemd-logind[324]: Watching system buttons on /dev/input/event10 (SEM USB Keyboard)
čec 15 08:58:23 adam-tuxedo systemd-logind[324]: Watching system buttons on /dev/input/event12 (SEM USB Keyboard Consumer Control)
čec 15 08:58:23 adam-tuxedo systemd-logind[324]: Watching system buttons on /dev/input/event13 (SEM USB Keyboard System Control)
čec 15 08:58:23 adam-tuxedo upowerd[326]: treating change event as add on /sys/devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2.1
čec 15 08:58:23 adam-tuxedo upowerd[326]: treating change event as add on /sys/devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2.2
čec 15 08:58:23 adam-tuxedo mtp-probe[2713]: bus: 1, device: 40 was not an MTP device
čec 15 08:58:23 adam-tuxedo mtp-probe[2712]: bus: 1, device: 41 was not an MTP device
čec 15 08:58:23 adam-tuxedo mtp-probe[2713]: checking bus 1, device 40: "/sys/devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2.1"
čec 15 08:58:23 adam-tuxedo mtp-probe[2712]: checking bus 1, device 41: "/sys/devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2.2"
čec 15 08:58:23 adam-tuxedo kernel: hid-generic 0003:1A2C:4324.0027: input,hidraw2: USB HID v1.10 Device [SEM USB Keyboard] on usb-0000:00:14.0-2.2/input1
čec 15 08:58:23 adam-tuxedo kernel: input: SEM USB Keyboard System Control as /devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2.2/1-2.2:1.1/0003:1A2C:4324.0027/input/input70
čec 15 08:58:22 adam-tuxedo kernel: input: SEM USB Keyboard Consumer Control as /devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2.2/1-2.2:1.1/0003:1A2C:4324.0027/input/input69
čec 15 08:58:22 adam-tuxedo kernel: hid-generic 0003:1A2C:4324.0026: input,hidraw1: USB HID v1.10 Keyboard [SEM USB Keyboard] on usb-0000:00:14.0-2.2/input0
čec 15 08:58:22 adam-tuxedo kernel: input: SEM USB Keyboard as /devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2.2/1-2.2:1.0/0003:1A2C:4324.0026/input/input68
čec 15 08:58:22 adam-tuxedo kernel: usb 1-2.2: new low-speed USB device number 41 using xhci_hcd
čec 15 08:58:22 adam-tuxedo kernel: hid-generic 0003:093A:2510.0025: input,hidraw0: USB HID v1.11 Mouse [PixArt USB Optical Mouse] on usb-0000:00:14.0-2.1/input0
čec 15 08:58:22 adam-tuxedo kernel: input: PixArt USB Optical Mouse as /devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2.1/1-2.1:1.0/0003:093A:2510.0025/input/input67
čec 15 08:58:22 adam-tuxedo kernel: usb 1-2.1: new low-speed USB device number 40 using xhci_hcd
čec 15 08:58:21 adam-tuxedo upowerd[326]: treating change event as add on /sys/devices/pci0000:00/0000:00:14.0/usb1/1-2
čec 15 08:58:21 adam-tuxedo kernel: hub 1-2:1.0: 4 ports detected
čec 15 08:58:21 adam-tuxedo kernel: hub 1-2:1.0: USB hub found
čec 15 08:58:21 adam-tuxedo kernel: usb 1-2: new high-speed USB device number 39 using xhci_hcd
čec 15 08:58:21 adam-tuxedo kernel: usb 1-2.2: USB disconnect, device number 38
čec 15 08:58:21 adam-tuxedo kernel: usb 1-2.1: USB disconnect, device number 37
čec 15 08:58:21 adam-tuxedo kernel: usb 1-2: USB disconnect, device number 36

Maybe this issues is not related, but if anynone have some ideas, I will be happy for any.
Thanks.

Hello. It seems that there is something wrong with USB mouse and keyboard or notebook itself. I don't know what (notebook refused to boot unless I connected USB mouse, and now after hour or so, it boots ok). Which also means that other mouse and other PC (both completly different) also have some USB problem. Not probable but possible. So for now I will not using USB mouse and keyboard with notebook (and maybe I will try some other USB devices).