Hi
Please check the jumpers, i tested IAR EWARM and the SDK 2.16 FlexSPI Octal NOR flash examples, it can work.
Board settings
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Connect pin 1-2 of JP41,JP42,JP43,JP44,JP45,JP62,JP64 and JP65.
Close JP63,JP66,JP67,JP68 and JP69.
You can refer to my picture.


BR
Hang