Ubuntu – Wacom Intuos S only recognized in Android Mode

Second edit: Since this question keeps getting attention, I want to put a clear disclaimer at the top: if you are experiencing this problem, it will likely be solved by pressing and holding the left-most and right-most button on your pad at the same time for a few seconds. You will notice that it has worked when the light at the top gets brighter. Avoid messing with anything else until you have tried this solution. Reinstalling drivers can make the problem worse.

The original title of this question was "Only left half of Wacom Intuos S is working". The text of the original question preserved below. I have since figured out part of the problem, so I am updating this question.

I am using a Wacom Intuos S on Ubuntu 18.04. If I plug it into the laptop, the device automatically goes into Android mode. This is a known issue with Ubuntu. This is confirmed by the output of libwacom-list-local-devices (output shown in the original question) as well as the output of lsusb which lists the vendor ID of the device as 2d1f (as noted in the link above on the issue). The tablet then behaves erratically.

I can toggle the pad to PC mode by holding the leftmost and rightmost button for a few seconds. The tablet then seems to successfully switch to PC mode: lsusb recognizes the device, the vendor ID updates to the correct value, and the indicator light turns on more brightly. However, now the device does not work at all: the cursor does not respond to the movement of the stylus, it is not recognised by Settings (gnome-control-center), and libwacom-list-local-devices does not list it at all. xsetwacom --list devices also comes up empty.

On my home laptop (very similar to my work laptop) switching the pad to PC mode fixes the issue: I can use the tablet without changing anything or updating any drivers. This is also true for a colleague, who was struggling with exactly the same issue (also on Ubuntu). This suggests to me that my attempt to get my drivers into their most recent versions on my work PC is actually what broke the tablet.

What do I need to do so that my tablet is recognized by my Ubuntu PC when it is in PC mode?

Original question text:

My new Wacom Intuos S connects to my Ubuntu laptop, and responds to input, but only its left half (or really, left third) works properly. In the image below I have marked the area that works properly.

If I move my stylus outside the rectangular area, my cursor still responds to vertical movement (i.e. moving my stylus still causes my cursor to go up and down) but no longer to horizontal movement (i.e. moving my stylus does not cause my cursor to move left to right).

Listing my devices with xsetwacom lists only my stylus and eraser — this is inconsistent with an example I found elsewhere, which lists also a cursor and a pad — but I am not sure if that relates to the problem.

mees@mees-ThinkPad-L480:~$ xsetwacom --list devices
Wacom Co.,Ltd. Intuos S stylus      id: 9   type: STYLUS    
Wacom Co.,Ltd. Intuos S eraser      id: 16  type: ERASER    

Running libwacom-list-local-devices seems to give a relevant hint to the problem:

[Device]
Name=Wacom Intuos S (Android Mode)
DeviceMatch=usb:2d1f:0374;
Class=Bamboo
Width=2
Height=4
IntegratedIn=
Layout=intuos-s-p3.svg
Styli=0;

[full output omitted, can report if necessary]

The reported height and width seem to match the aspect ratio of the part of the device I am actually able to use. I can find the config file (?) that lists the information above, and simply edit the width field to have a different value (e.g. 5), but that does not actually change anything except the output of libwacom-list-local-devices (I have changed it back to the default value of 2 for now).

This problem seems to be Ubuntu-specific: I have tried the tablet on my boyfriend's Windows laptop, and it works correctly (after installing the relevant drivers). I have also tried it on my personal laptop, which is nearly identical to my work laptop (also a Lenovo Thinkpad with Ubuntu 18.04) and I have the same problems.

What can I do to get my Intuos pad to work properly? Or how can I effectively troubleshoot?

Please let me know if I should provide any further/more detailed information.