Altered pLDDT scores after running FastRelax on AlphaFold Multimer output pdb files

Hello,

I hope this message finds you well. I noticed after running FastRelax on output pdb files from AlphaFold Multimer that the pLDDT scores encoded in the B-factor fields have been altered. Is there a way to avoid this and maintain the original pLDDT scores? I have attached the code I am running below. 

Thank you,

Franz

!pip install pyrosettacolabsetup
import pyrosettacolabsetup; pyrosettacolabsetup.install_pyrosetta()
import pyrosetta; pyrosetta.init('-ex1 -ex2 -use_input_sc -no_optH false -flip_HNQ -nstruct 1')
from pyrosetta import *
from pyrosetta.teaching import *
#input pdb file
pose = pose_from_pdb('unrelaxed_97.pdb')
#shorten name
fr = pyrosetta.rosetta.protocols.relax.FastRelax()
#get ref2015 scoring function
fr.set_scorefxn(get_score_function())
#flags from benchmark study Yin et al., 2022
fr.constrain_relax_to_start_coords(True)
fr.coord_constrain_sidechains(True)
fr.ramp_down_constraints(False)
#run FastRelax
fr.apply(pose)
#download relaxed structure
pose.dump_pdb('relaxed_97.pdb')