Perhaps, during the gameplay, the hand just disappeared. If you save and reload the game, the problem goes away, but not all achievements are saved. If a lot has been done since the last checkpoint, reloading is not the best option. At the same time, the possibility of interacting with the world is also absent due to the disappearance of the hand.
If restarting the game is not a good solution, since you have completed quite a lot of the story, we recommend trying to switch your main hand from left to right and vice versa. Faced with a similar problem, it works quite often. Then you can set your preferred hand back, everything should work.
This is not a complete solution, as a lot depends on the developers. We’ll have to wait for the fix with the next updates.