DCLE diffuse into Bulk solution from membrane after 1.8 ns equilbration in HMMM (Charmm-Gui)

GROMACS version: 2021.1
GROMACS modification: No
Here post your question : I have made a Highly Mobile Membrane-Mimetic Model (HMMM) using CHARMM-GUI which after a equilibration of 1.8 ns, few DCLE diffuse into the bulk solution. Is this a common occurrence or I’m doing something wrong

is there way to keep DCLE in between the headgroup

system size 14 14 13

atoms 232019

Position restraints 20 kcal/mol^/nm^2