Critical Issue
The Tx FIFO almost full threshold parameter of the Intel® Stratix® 10 Hard IP for PCIe* Gen 3 x16 variant is marginal. You may see corrupted data without LCRC error or Completion Time Out error that does not cause a link recovery to occur.
Other IP variants like PCIe* Gen 3 x8 and Gen 3 x4 are not affected.
There is a related KDB.
This problem is fixed beginning with the Intel® Quartus® Prime Pro Edition Software version 20.4.
To resolve this problem, you should regenerate the Intel® Stratix® 10 Hard IP for PCIe* Gen 3 x16 variant and recompile the design with the Intel® Quartus® Prime Pro Edition Software version 20.4 or later version to incorporate the fix.