The address should be 0x45 for normal operation.
It only show’s up with 0x56 if the STM32 is in bootloader mode.
If you can read the address with i2cdetect no driver blocks access to it. Have you enabled the DT Overlay again?
Are you sure you have board revision 1.8? This is not the same as the firmware version.
If you are unsure it’s also printed on the PCB