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.
Device Family: Intel® Stratix® 10
Intel Software: Quartus Prime Pro
Last Modified: May 01, 2020
Version Found: v20.1
Version Fixed: v20.2
Bug ID: 1507935938