Interpretation of Nonzero 14-LJ and 14-Coul Terms for Nonbonded Groups

GROMACS version: GROMACS/2023.3-foss-2022b-CUDA-12.1.1-PLUMED-2.9.2
GROMACS modification: No

My dynamics looks normal but there are nonzero interactions for 14-LJ and 14-Coul terms. It is my understanding that these terms should be exactly 0 for nonbonded molecules. My force field is OPLS with custom parameters for some ligands and cofactors. The dynamics looked normal, but these 14-LJ/Coul terms are very concerning to me. I’m using the pull code if that matters.

EDIT: I think its a bug with the energygrps reporting in GROMACS 2023 version, because I ran the same dynamics and analysis with the same topology on GROMACS 2021 and I get the expected 0s for all the intermolecular 14-LJ and 14-Coul energies.

Any help or further clarification would be greatly appreciated!