OnePlus tries to fix touchscreen issues with new update for OxygenOS
You can download the firmware directly from inside the announcement where you will find the patch for the touchscreen issue. There you will also find the tool needed if you haven’t already installed the OxygenOS version and this should let you flash the latest version from CyanogenMod 11 or 12 without losing any data. This tool has been developed by XDA devs and Fastbot Mobile devs, which means it could have some issues on the long run. You will find instruction on the installation of the tool in the source link below.