Nstatus pin is toggling on power on

hi,

I had designed one custom board with cyclone5 (5CGTFD7D5F27I7N) FPGA.

I am trying to boot FPGA from SPI flash.

FLASH programmed successfully by .jic file but at power on -off FPGA is not loading from SPI QUAD FLASH.

while observation we find that ,at power on nstatus pin is toggling.

But when we program fpga with .sof than nstatus going high.

so what is the reason for this and how to overcome it ??

tramp(between 1.1 and 3.3v)=22 millisecond in our board.

power sequencing is -> 1.1v -> 1.2v ->2.5v -> 3.3v.

Thanks & Regards

DEEPAK