Due to a problem in the Avalon® -MM Intel® Stratix® 10 Hard IP for PCI Express® IP core in Intel® Quartus® Prime Pro Edition software version 20.3, you may see following issues:
1. PCIe BARs are not accessible after core configuration in Configuration via Protocol (CvP) design;
2. Host system hangs and auto restarts when host CPU triggers full-chip reconfiguration via PCIe, such as Remote System Update (RSU) over PCIe.
This issue has been fixed in Intel® Quartus® Prime Pro Edition software version 20.4 and later.
You can also install the following patch for Intel® Quartus® Prime Pro Edition software version 20.3, :