'Problem with manually allocating memory address for a pointer

I am trying to work with flash memory on MPC5748G - a microcontroller from NXP running FreeRTOS 10.0.1, and I get some behaviour that I can't understand.

I am allocating memory manually, and the assignment seems not to work. However, I can reach the value at the address when using 'printf' - but only from the same function. (I'm using the copy of a pointer, to make sure that some sore of compiler optimisation doesn't take place)

void vFlashTask(void* pvParameters){
   vTaskDelay(1000);
   FLASH_DRV_Init();
   uint32_t* val_ptr; 
   uint32_t* val_ptr_cpy;
   val_ptr = (uint32_t *)0xFB8000;
   val_ptr_cpy = val_ptr;
   
   *val_ptr = 444;

   DBGPRINTF("Task| value at xFB8000:%d", *val_ptr_cpy);
   
   getValTest();
   vTaskDelay(1500);
   vTaskDelete(NULL);
}

void getValTest(){
   uint32_t* val_ptr;
   val_ptr =(uint32_t *)0xfb8000;
   DBGPRINTF("getValTest| value at xFB8000:%d", *val_ptr);
}

Gives back (in UART Terminal):

   [../include/flash.c:26]: Task| value at xFB8000:444
   [../include/flash.c:37]: getValTest| value at xFB8000:-1

I am attaching also the screenshot from the debugger, which clearly shows that however memory at the xFB8000 is uninitialized (it has the value of 0xffffffff), but still, the printf function manages to print the correct value(?).

My DBGPRINTF macro:

#define DBGPRINTF(f, ...)           dbgPrintf("[%s:%d]: " f "\n", __FILE__, __LINE__, __VA_ARGS__)

void dbgPrintf(const char *format, ...){
    va_list args;
    va_start(args, format);
    int len = vsnprintf((char*) uart_buffer, UART_BUFFER_SIZE - 1, format,  args);
    UART_SendDataBlocking(&uart_pal1_instance, (const char *)uart_buffer, len, UART_TIMEOUT);
    va_end(args);
 }

I would really appreciate any help or suggestions.

My compiler flags:

\S32DS_Power_v2.1\eclipse\../S32DS/software/S32_SDK_S32PA_RTM_3.0.3/rtos/FreeRTOS_PA/Source/portable/GCC/PowerPC" -I"C:\NXP\S32DS_Power_v2.1\eclipse\../S32DS/software/S32_SDK_S32PA_RTM_3.0.3/middleware/tcpip/tcpip_stack/ports/OS" -I"C:\NXP\S32DS_Power_v2.1\eclipse\../S32DS/software/S32_SDK_S32PA_RTM_3.0.3/middleware/tcpip/tcpip_stack/ports/platform/generic/gcc/setting" -I"C:\NXP\S32DS_Power_v2.1\eclipse\../S32DS/software/S32_SDK_S32PA_RTM_3.0.3/middleware/tcpip/wolfssl/wolfssl" -I"C:\NXP\S32DS_Power_v2.1\eclipse\../S32DS/software/S32_SDK_S32PA_RTM_3.0.3/middleware/tcpip/wolfssl" -I"C:\NXP\S32DS_Power_v2.1\eclipse\../S32DS/software/S32_SDK_S32PA_RTM_3.0.3/rtos/FreeRTOS_PA/Source" -I"C:\NXP\S32DS_Power_v2.1\eclipse\../S32DS/software/S32_SDK_S32PA_RTM_3.0.3/platform/pal/inc" -I"C:\NXP\S32DS_Power_v2.1\eclipse\../S32DS/software/S32_SDK_S32PA_RTM_3.0.3/platform/drivers/src/flash_c55" -O1 -g3 -Wall -c -fmessage-length=0 -msdata=eabi -mlra -funsigned-bitfields -ffunction-sections -fdata-sections -fno-common -Wno-address -mcpu=e200z4 -specs=nosys.specs -mbig -mvle -mregnames -mhard-float --sysroot="C:\NXP\S32DS_Power_v2.1\eclipse\../S32DS/build_tools/powerpc-eabivle-4_9/powerpc-eabivle/newlib"

c pointers

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'Problem with manually allocating memory address for a pointer

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