We are experiencing the same problem with the design on our board. We are using the optional 'secondary pinmux' port pins to connect to our QSPI flash. We can load and run the "evkbimxrt1050_flexspi_nor_polling_transfer" example project from RAM. It erases, writes, reads, and verifies the external QSPI flash device on our board. We are using the ISSI IS25LP016D-JBLE (16Mb) part. We are unable to load our XIP image using the MfgTool (BLHost) over UART (no OpenSDA chip on our board) and receive the following message: "kStatus_FlexSPINOR_SFDP_NotFound", when we try using the blhost -V -p COM7,115200 -- configure-memory 0x09 0x2000 command. We have tried several QCB (QSPI Configuration Block) option settings with the -- fill-memory 0x2000 0x04 0xC0000006; 0xC0000046 ('secondary pinmux' setting); 0xC0000106 (Quad Enable in bit 6 on this device); 0xC0000146, etc. None work. A similar error is received while trying to load the "evkbimxrt1050_led_blinky" image using the MCUXpresso IDE via a LPC-Link2 over the SWJ-DP interface (using SWD). We get this message:

When using the following Project Properties->C/C++ Build->MCU Settings:

Yet, again, when we load and run the "evkbimxrt1050_flexspi_nor_polling_transfer" example project from RAM, everything works as expected.
We are using MCUXpresso IDE v10.3.0 [Build 2200] [2018-12-03] and SDK_2.x_EVKB_IMXRT1050 version 2.4.2, manifest version 3.3.0.
Any help will be greatly appreciated.
Regards and thanks in advance,
-Roger