Comment 5 for bug 1854895

The last working version was the previous kernel: (4.15.0-70).

ii linux-image-4.15.0-70-generic 4.15.0-70.79 amd64
ii linux-image-4.15.0-72-generic 4.15.0-72.81 amd64
ii linux-image-generic 4.15.0.72.74 amd64

Information below is with the working kernel (4.15.0-70):
uname -a output:
Linux kububb 4.15.0-70-generic #79-Ubuntu SMP Tue Nov 12 10:36:11 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux

$ inxi -Fxxxz
System:
  Host: kububb Kernel: 4.15.0-70-generic x86_64 bits: 64
  compiler: gcc v: 7.4.0 Desktop: KDE Plasma 5.12.9 tk: Qt 5.9.5
  wm: kwin_x11 dm: SDDM Distro: Ubuntu 18.04.3 LTS (Bionic Beaver)
Machine:
  Type: Laptop System: Dell product: Inspiron 15-3567 v: N/A
  serial: <filter> Chassis: type: 9 serial: <filter>
  Mobo: Dell model: 0FGN4M v: A00 serial: <filter> UEFI: Dell
  v: 01.07.00 date: 04/07/2017
Battery:
  ID-1: BAT0 charge: 29.9 Wh condition: 29.9/41.4 Wh (72%)
  volts: 16.9/14.8 model: SMP DELL VN3N047 type: Li-ion
  serial: <filter> status: Full
CPU:
  Topology: Dual Core model: Intel Core i3-6006U bits: 64 type: MCP
  arch: Skylake rev: 3 L2 cache: 3072 KiB
  flags: lm nx pae sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx
  bogomips: 7968
  Speed: 500 MHz min/max: 400/2000 MHz Core speeds (MHz): 1: 500
  2: 500
Graphics:
  Device-1: Intel Skylake GT2 [HD Graphics 520] vendor: Dell
  driver: i915 v: kernel bus ID: 00:02.0 chip ID: 8086:1916
  Display: x11 server: X.Org 1.19.6 driver: intel
  compositor: kwin_x11 resolution: 1366x768~60Hz
  OpenGL: renderer: Mesa DRI Intel HD Graphics 520 (Skylake GT2)
  v: 4.5 Mesa 19.0.8 compat-v: 3.0 direct render: Yes

$ xinput list
⎡ Virtual core pointer id=2 [master pointer (3)]
⎜ ↳ Virtual core XTEST pointer id=4 [slave pointer (2)]
⎜ ↳ YSPRINGTECH USB OPTICAL MOUSE id=10 [slave pointer (2)]
⎜ ↳ Synaptics TM3096-006 id=12 [slave pointer (2)]
⎜ ↳ SynPS/2 Synaptics TouchPad id=16 [slave pointer (2)]
⎣ Virtual core keyboard id=3 [master keyboard (2)]
    ↳ Virtual core XTEST keyboard id=5 [slave keyboard (3)]
    ↳ Power Button id=6 [slave keyboard (3)]
    ↳ Video Bus id=7 [slave keyboard (3)]
    ↳ Power Button id=8 [slave keyboard (3)]
    ↳ Sleep Button id=9 [slave keyboard (3)]
    ↳ Integrated_Webcam_HD: Integrate id=11 [slave keyboard (3)]
    ↳ Intel HID events id=13 [slave keyboard (3)]
    ↳ Dell WMI hotkeys id=14 [slave keyboard (3)]
    ↳ AT Translated Set 2 keyboard id=15 [slave keyboard (3)]
$

Relevant to touchpad:
$ cat /proc/bus/input/devices

I: Bus=0011 Vendor=0002 Product=0007 Version=01a1
N: Name="SynPS/2 Synaptics TouchPad"
P: Phys=isa0060/serio1/input0
S: Sysfs=/devices/platform/i8042/serio1/input/input7
U: Uniq=
H: Handlers=mouse1 event7
B: PROP=5
B: EV=b
B: KEY=e520 10000 0 0 0 0
B: ABS=660800011000003