can you share the pbc command that you used in this case?

printf '0\n' | gmx trjconv -s md_0_10.tpr -f md_0_10.xtc -o md_0_10_noPBC.xtc -pbc mol -ur compact

Selected 'system'

Try to visualize the events by loading the trajectory in VMD. It may give you some clues about what is wrong.

@Ronald - can you try " -pbc nojump" instead of " -pbc mol -ur compact "

Hey guys.

Thanks for helping! After inspect the trajectory on VMD and change -pbc flag, I managed to find out what is going on. I use an sort of automatized in-house script to run gromacs that wasn't using the PBC corrected .xtc file for calculate the radius of gyration. So, I replaced manually and it works fine. It was a silly mistake but in the bright sight was good to observe the importance of correct for PBC.

Thanks again, folks!

Cheers!