Description
Although documented as supported in Intel® Stratix® 10 General Purpose I/O User Guide and allowed in Intel® Quartus® Prime Pro Edition software version 20.1 and earlier, the weak pull-up feature is in fact not supported in bank 3C of Intel® Stratix® 10 GX 400 and SX 400 devices.
Resolution
The weak pull-up option for bank 3C is scheduled to be removed starting with the Intel Quartus Prime Pro Edition software version 20.2.