STM32 HAL_FLASH_Program not working as expected - stm32

Question

I'm trying to program FLASH using HAL_FLASH_Program() function. Precisely speaking, I've written a function which is expected to write two measurements
to flash at a set time interval (e.g. 3 seconds). However, when called, the function manages to write only the first one while ignoring the second one. Can't HAL_FLASH_Program be used twice? What am I doing wrong? I just want to mention that I'm utterly new to STM32 programming, so any helpful suggestions would be much appreciated. Here is the code:
void writeFlash(void){
mem = returnPointerToFirstEmptyAddressInSector();
Address = (uint32_t)mem;
var1.f = Temperature;
var2.f = SD;
HAL_FLASH_Unlock();
__HAL_FLASH_CLEAR_FLAG(FLASH_FLAG_EOP | FLASH_FLAG_OPERR | FLASH_FLAG_WRPERR | FLASH_FLAG_PGAERR | FLASH_FLAG_PGSERR | FLASH_FLAG_PGPERR);
HAL_FLASH_Program(TYPEPROGRAM_WORD, Address, var1.i );
Address++;
HAL_FLASH_Program(TYPEPROGRAM_WORD, Address, var2.i);
HAL_FLASH_Lock();
}

Answer 1

The address is not properly aligned
The declaration of Address is not shown, but from the line
Address = (uint32_t)mem;
I'd guess it's an unsigned long. Later, you are incrementing Address after the first write with
Address++;
and use this value to program the second value. But since Address is presumably an integer, not a pointer type, it would be incremented by one instead of the word size (4), and pointing to an address that is partially overlapping the previously written value, and not aligned for word-sized writes. The second write operation would inevitably fail. As #JMA suggests in the comments, check the return value of HAL_FLASH_Program(), and the error code
uint32_t ret = HAL_FLASH_Program(TYPEPROGRAM_WORD, Address, var2.i);
switch(ret) {
case HAL_OK:
break;
case HAL_TIMEOUT:
printf("HAL_FLASH_Program() timeout!\n");
break;
case HAL_ERROR:
printf("HAL_FLASH_Program() error 0x%08x, see *hal_flash.h for bit definitions\n", HAL_FLASH_GetError());
break;
default:
printf("HAL_FLASH_Program() returned unknown status %lu\n", ret);
}
Write a double word at once
The HAL library supports writing 64 bit values at once, so you can write two 32 bit integers in one operation.
HAL_FLASH_Program(TYPEPROGRAM_DOUBLEWORD, Address, ((uint64_t)var2.i << 32) | var1.i);
Just ensure that Address is aligned to a doubleword boundary, i.e. divisible by 8.