@hek right :) sizeof uint32_t : 4

it works with :

#define EEPROM_SLEEP_DURATION_ADDRESS 0

uint32_t sleepDurationInS = 86399;

hwWriteConfigBlock((void*)&sleepDurationInS, (void*)(EEPROM_LOCAL_CONFIG_ADDRESS+EEPROM_SLEEP_DURATION_ADDRESS), 4);

 hwReadConfigBlock((void*)&sleepDurationInS, (void*)(EEPROM_LOCAL_CONFIG_ADDRESS+EEPROM_SLEEP_DURATION_ADDRESS), 4);

@tekka Hi, I found my mistake ! You were absolutely right when you said there is no sign of MYSBootloader in my GW log...
But now I know why :) :
I use an USBasp Programmer with Arduino IDE for upload my bootloader and my sketch..., and I mistakenly thought that when I upload bootloader then sketch, it keep bootloader.....but NOT, it overwrite bootloader :(
I fix it by uploading the xxx.with_bootloader.hex file generated by Arduino IDE when compile.

Sorry for the inconvenience and thank you for your help