Thank you very much for sending the requested screenshots.
Please try all of our suggestions below:
1. We have done a quick research and found a quite similar issue in the lenovo forum site.
Could you please try updating your Yoga C640’s GPU, Intel Chipset, Intel Sensor Hub and Yoga Mode Control Application drivers as suggested posted by a Lenovo support here: https://forums.lenovo.com/t5/Lenovo-Yoga-Series-Notebooks/Yoga-C640-13IML-Touch-screen-not-working/m-p/5095730?page=1#5413877
2. Open the Device Manager the try to disable-enable the touch device underneath Human Interface Devices.
3. On Device Manager, please try to reinstall the devices underneath „Other Devices“.
4. Run system file checker to repair missing or corrupter system files. Just run Command Prompt as Administrator then type the command: sfc /scannow