How to avoid oscillations when NVT used

Dear Lammps users
I have a simulation system. There is a graphite pore, and a graphene above it covering the pore. The DRIP and REBO pair style were used. I looked forward to the graphene’s center area sinking slightly. But as NVT used, the graphene oscillated up and down. Do you have any suggestions to make the graphene’s center area sinking slightly without oscillation, meanwhile keeping room temperature.

why should the sheet NOT oscillate (or “flap around”) if you put kinetic energy into it?
keep in mind that such low frequency modes require rather little energy to become active.