I think I made the mistake of using cloud saves on two different computers when did a run Mutation, Iron Mode and Toy Seller achievements. I started the run on one pc then finished it on a second one. I did not get any of those achievements. It might be worth mentioning that I found the first 2 toys on the first pc and the 3 toy on the second.

However when I got home I just reloaded the last checkpoint of the game and "completed" the it again where I received Mutation and Iron Mode. But no Toy Seller, damn it. Then I thought, "Maybe I can find the last one again" and then started a New Game+ in search of the missing toy. No dice... when I got to the place where it should be hanging it wasn't there. Instead it was hanging in Artyom's room. Damn it.

After a few weeks of not playing the game, I decided to bite the bullet and wipe my save game, plow through it, start a New Game+ and then hopefully find the toys... but now, at the last train section of the game, I see them, all 3 toys in Artyom's room. So I'm a bit reluctant to complete this run and start the New Game+ run.

I usually don't go for achievements but I wanted to in this game for some reason. So it really stings that the first time I do go for 100% achievements I run into what I can only assume to be a bug that prevents me from doing so. I have not been able to find any solutions to this so far, do any of you guys know any?

Okay so first of there is a file called user.cfg in the main game folder that stores achievement data.
Second, there is a file called profile.cfg in your saved_games folder(in the main game folder), one for each save slot that tracks collectibles such as notes and postcards. It is my guess that the toys are stored in this file as well.

Now since you said that you swicthed computers, im going to guess that the user.cfg maybe did not get stored in your cloud saves and therefore the new user.cfg that came with your new install only thinks you've picked up the last toy and not the 2 previous ones.

So the reason you are seeing all 3 toys in the train (in theory) is because you started a newgame+ on the same save slot which uses the same profile.cfg file that stores collectibles. So... technically you could delete this file (resetting collectibles) and then try and pick up the toys again.

And if that does not work you could delete the user.cfg file so that the game generates a new one so that achievement data is reset. This also resets difficulty and keybinds potentially screwing over your savegame if you are going for difficulty related achievements. So start a new game from a slot you've deleted the profile.cfg file from if you are going to do this. I can't remember how the game generates a new user.cfg, it used to be you just deleted it and then launched the game and a new one came into existance. But last I tried one would not appear and the game started without one and as a result I could not make it past the titlescreen because the file contains all keybinds. So back yours up if you are going to try it. My guess is deleting it and then reinstalling the game/validating the game files in gog might create a new one but I've yet to try.

I'll try deleting profile.cfg, start a New Game+ and see what happens. I completed the game despite seeing the toys dangling so I could get right into it, if there was a potential solution. Thanks for the heads up! Toy Seller is however the last achievement (besides a few in Sam's Story) which I'm missing, so I'll go Reader mode for this run.

From what I can tell, deleting profile.cfg and starting a New Game+ did not do the trick. I have not been able to find the fish necklace anywhere in Volga...