Issues of less number of water using spce water model

GROMACS version:2020.4
GROMACS modification: Yes
Here post your question: I am running some replica runs of a simulation already done beforehand. In the previous simulations, some 54k water was used while solvating the structure. However, my box uses 53k spce water to solvate the system. The simulations are identical,uses all same parameters and the same starting structures. Someone pointed out the problem can be in the spc216.gro; hence I opened it and saw that it mentions SPC-MODEL. Kindly point me toward the issue here, is it a possibility that the previous sims used a different water structure file to solvate?