Hi Maggie,
We appreciate you posting the query to Microsoft Community. We would like to know, are you having any error message or pop-up related to SynKernelDiags?
Upon trying to research, we found that it was identified as a log file, generated by either your Mouse, Touchpad, or Keyboard diagnostic system. This can be stopped by modifying the settings of your device diagnostics. About how you can do it accurately, you will need to reach your device manufacturer's support expert. But after you connected with them, please feel free to update your post, so we can continue here if necessary.
Kind regards.