Can't communicate MT25Q flash over Serial Flash Controller II Intel FPGA IP with quartus_pgm --nios2 or Nios Flash Programmer-- Error 18927 FAILED when using quartus_pgm

I Can't communicate (with Nios Flash Programmer or quartus_pgm) with a flash chip ( MT25QU1G ) on an Arria V via the Serial Flash Controller II on the NIOS processor. (We can however use the chip to configure the FPGA using AS over the dedicated pins -- programmed through a .jic with Quartus Prime Programmer)

quartus_pgm --nios2 --debug

with and without every permutation of

--base=0x10000000

--epcq

--epcs

--csr=0x7000

--dualdie

All these commands fail with:

Info: Using INI file C:/intelFPGA/18.1/quartus/bin64/quartus.ini

Info (18932): Using cable "EthernetBlasterII on 192.168.5.50 [EthernetBlasterII]", device 1, instance 0x00

Info (18932): Resetting and pausing target processor:

Error (18927): FAILED

Info (18932): Leaving target processor paused

Error: Quartus Prime Programmer was unsuccessful. 1 error, 0 warnings

Error: Peak virtual memory: 4403 megabytes

Error: Processing ended: Thu Dec 12 13:53:03 2019

Error: Elapsed time: 00:00:03

Error: Total CPU time (on all processors): 00:00:00

Additional Info:

==========================

The Programmer (Serial Flash Controller II IP) is running at 10Mhz (well below fMAX of 50Mhz)

(System ID & Timestamp are accurate)

FYI: From system.h

#define ALT_MODULE_CLASS_epcq_controller2_0_avl_csr altera_epcq_controller2

#define EPCQ_CONTROLLER2_0_AVL_CSR_BASE 0x7000

#define EPCQ_CONTROLLER2_0_AVL_CSR_FLASH_TYPE "MT25QU01G"

#define EPCQ_CONTROLLER2_0_AVL_CSR_IRQ 6

#define EPCQ_CONTROLLER2_0_AVL_CSR_IRQ_INTERRUPT_CONTROLLER_ID 0

#define EPCQ_CONTROLLER2_0_AVL_CSR_IS_EPCS 0

#define EPCQ_CONTROLLER2_0_AVL_CSR_NAME "/dev/epcq_controller2_0_avl_csr"

#define EPCQ_CONTROLLER2_0_AVL_CSR_NUMBER_OF_SECTORS 2048

#define EPCQ_CONTROLLER2_0_AVL_CSR_PAGE_SIZE 256

#define EPCQ_CONTROLLER2_0_AVL_CSR_SECTOR_SIZE 65536

#define EPCQ_CONTROLLER2_0_AVL_CSR_SPAN 64

#define EPCQ_CONTROLLER2_0_AVL_CSR_SUBSECTOR_SIZE 4096

#define EPCQ_CONTROLLER2_0_AVL_CSR_TYPE "altera_epcq_controller2"

#define ALT_MODULE_CLASS_epcq_controller2_0_avl_mem altera_epcq_controller2

#define EPCQ_CONTROLLER2_0_AVL_MEM_BASE 0x10000000

#define EPCQ_CONTROLLER2_0_AVL_MEM_FLASH_TYPE "MT25QU01G"

#define EPCQ_CONTROLLER2_0_AVL_MEM_IRQ -1

#define EPCQ_CONTROLLER2_0_AVL_MEM_IRQ_INTERRUPT_CONTROLLER_ID -1

#define EPCQ_CONTROLLER2_0_AVL_MEM_IS_EPCS 0

#define EPCQ_CONTROLLER2_0_AVL_MEM_NAME "/dev/epcq_controller2_0_avl_mem"

#define EPCQ_CONTROLLER2_0_AVL_MEM_NUMBER_OF_SECTORS 2048

#define EPCQ_CONTROLLER2_0_AVL_MEM_PAGE_SIZE 256

#define EPCQ_CONTROLLER2_0_AVL_MEM_SECTOR_SIZE 65536

#define EPCQ_CONTROLLER2_0_AVL_MEM_SPAN 134217728

#define EPCQ_CONTROLLER2_0_AVL_MEM_SUBSECTOR_SIZE 4096

#define EPCQ_CONTROLLER2_0_AVL_MEM_TYPE "altera_epcq_controller2"