Did you see all the comments about needing to power-cycle after writing certain option bytes?Until this happens, you will just read back the old (shadow) value.

Something else I forgot to mention previously with our Option Byte issues was that we never managed to get HAL_FLASH_OB_Launch to work (for the second core's vector table on the WL54) and always has to power-cycle the chip for the new settings to tak...

Glad it helped!For reference, the issues I had on the WL5x with option bytes were:When including option bytes in the hex file, ST-Link + STM32Cube Programmer would completely mess up what was programmed, often resulting in write protected regions bei...

For other people finding this later, I've managed to resolve the issue on some boards by ensuring the SUBGHSPISD bit is SET in the option bytes to disable security on SPI3.I've found what option bytes do on this chip (especially if self programming, ...

Did you ever get anywhere with this or was it put down to a fault chip?I believe we're seeing the same symptoms - all SUBGHZSPI/SPI3 registers showing zero despite SUBGHZSPIEN flag being enabled in RCC.