Shaggy Sergei rescue glitch. Thread - Old Good STALKER Evolution mod for S.T.A.L.K.E.R. Shadow of Chernobyl

Hi guys, I thought I'd better bring to your attention this issue as it may be a glitch in the game:
There is this mission when you first enter the Dark Valley, where you are asked to save the Duty member (Shaggy Sergei) held captive by the bandits.
So I went there, cleaned all the place (except for the Profiteer) and open the door (the door controls on the wall can be distroyed with the knife - and possibly with other weapons as well - btw.)

Problem is Shaggy won't step out of its cell even if the door is open. He even won't talk to me, just keeps repeating "Hey Stalker, open the door..." although the door is wide open.
When I replayed the whole mission I managed to get him out of the cell but he got stuck at the gate of the compound. He simply stood at the gate and won't go further (although there were no enemies or monsters nearby.

Thank you for your time and efforts. I really missed the good old and enhanced Stalker without dramatic changes in the storyline, like they did in Lost Alpha. Keep up the good work. ☺

This has nothing to do with the theme: Juste a question, can we improve weapons in this mod? Thank you ( i'm french)