Please refer to the following thread for the relationship about the size.
How to solve the issue that ssd are not entiely availiable after full disk encryption - #5 by KevinFFF
In your case, please modify the num_sectors from 60604416 to 461373440(*512/1024/1024/1024=220GiB) in flash_l4t_nvme.xml.
and flash with the same command.