Due to a problem in the Intel® Quartus® Prime Pro Edition software version 21.1, if you program the Raw Binary File (.rbf) with a matching key (expect to pass), then program the RBF with a mismatched key (expect to fail), then try to program the RBF with a matching key (expect to pass), however the process will fail and you will see the following message:
Error (18944): CONF_DONE pin failed to go high in device 0. Make sure all communication cables are securely connected, select a different device, check the power on the target system, or make sure all nCE pins are connected to GND.
A patch is available to fix this problem for the Intel® Quartus® Prime Pro Edition software version 21.1. Download and install Patch 0.06 from the appropriate link below.
This patch is scheduled to be included in a future release of the Intel® Quartus® Prime Pro Edition software.