Is there a known problem with VREF pin reporting in the Intel® Quartus® Prime Pro Edition Software version 21.4 when using Intel® Stratix® 10 devices?

Yes, due to a problem in the Intel® Quartus® Prime Pro Edition Software version 21.4, the "All Package Pins" report will show incorrect VREF requirements for Intel® Stratix® 10 devices when no GPIOs in the respective I/O bank use a voltage standard that requires a VREF.

To work around this, compare the Pin Planner settings for the respective bank with the Intel Stratix 10 Device Datasheet I/O Standard Specifications VREF requirement. 
If all your pins in the bank do not require a VREF, then connecting the VREF pin to GND is safe.

This problem will be fixed in a future release of the Intel® Quartus® Prime Pro Edition Software.