too long fene bond in the boundary condition

Hi

I am trying to simulate a polymer with FENE potential. When the viscosity is on and it is going to pass through the periodic boundary condition I get :

WARNING: FENE bond too long: 683515 54 55 1.47855 (…/bond_fene.cpp:91)
WARNING: FENE bond too long: 683516 54 55 2.46285 (…/bond_fene.cpp:91)
WARNING: FENE bond too long: 683516 53 54 1.98836 (…/bond_fene.cpp:91)
WARNING: FENE bond too long: 683517 54 55 3.36576 (…/bond_fene.cpp:91)
ERROR on proc 1: Bad FENE bond (…/bond_fene.cpp:92)

I do not have this problem when I turn the viscosity off. This just seems ironic to me.

dielectric 3.0
bond_style fene

bond_coeff 1 30 1.5 1 1
special_bonds lj/coul 0 1 1
group poly type 1

pair_style coul/debye 1.4 2.1
pair_coeff * *
fix 111 all viscous 3

fix 134 all langevin 1.0 1.0 11.8 12321
fix 221 all nve
minimize 0.0 1.0e-8 1000 100000

fix forc poly “some forces”

Thanks in advance for your help.