Until now, you can't erase EEPROM with CubeProgrammer :
In EEPROM technology, you can write at any time without erasing the memory, which is not the same case for flash memory; where you can write only after you have deleted before.
So the solution is as follows:
Either you leave EEPROM as it is and write when you need it or you write the reset value: 0x00000000.