A common issue with tablets and some touchscreen laptops is that the touchscreen does not work without power connected.

I have found a solution that works on my device and seems pretty easy to do for other devices.

Thinkpad 8 - Touchscreen not working after Windows 10 Fall Creators Update - Page 3 - Lenovo Community

I had to also add SelectiveSuspendOn and set to 1 - not there for a clean install.

I had to mess around changing permissions in second registry edit which was needed as it happens.

How to Take Ownership (Permission) of Protected Registry Key in Windows 10 | Password Recovery

Now I have my Linx8 on 16299.19 working properly.