Due to a problem with the Intel® Quartus® Prime Pro edition version 19.1, the synchronizer chain "altera_std_synchronizer_nocut" might have an unsafe Mean Time between Failure (MTBF) when it follows an asynchronous transfer. This is because the synchronizer chain is merged with retimer-created registers, which breaks the synchronizer requirements. Without a synchronizer, an asynchronous transfer will have a very low MTBF and be reported as being unsafe.
To work around this problem for the Intel® Quartus® Prime Pro Edition software, turn off the early retimer by writting the following assignment in the Quartus Settings file (.qsf):
"set_global_assignment -name FITTER_EARLY_RETIMING OFF"
This problem is scheduled to be fixed in a future Intel® Quartus® Prime Pro Edition software release.