NPC (Squint) not responding, Can't Finish Quest

I was waiting Stalker 2 for a long time and i played 4-5 hours in the first play. Game is good but i have a problem.

After finding artifact and getting out of the cave, i returned to the windmill to give it to Squint. But he's standing on the ladders and not responding. There's no interaction button appearing on him and you can't speak to him. So i can't finish the quest and it's annoying. It's not like npc stuck somewhere, it's just he's standing. I started the game from the previous save file (on cave) and got the artifact again and went to windmill. No solution.

Is there a solution to this? Maybe someone had the same issue.

Want to play the game more but this became a letdown for me.