What driver did you use?
For me original GE 90 Series works fine, but Modbus TCP that is listed in ProFace manual doesn't work.
You will want to use the GE series 90-30 driver. I have found that the symbols are reversed on some of the hmi's however. IE, Q and I are backwards respective to how they should be. Also, SR's do not display correctly on the proface, no matter how you configure the robot (make sure to reference the fanuc HMI user guide). Lastly, integer scaling by default in the proface often is incorrect.
Proface makes my favorite HMI's, but they leave much to be desired when it comes to integrating with the fanuc.
Also, to make sure: did you purchase the SNPX option on the fanuc? This is a software option that must be purchased outside of configuration of the SNPX settings.
Sorry for the late response.