Tomb Raider: Underworld

Some time ago i know but in the Southern Mexico Level it says you have to replay the level to get two collectibles but that is wrong. As you get back up to the top with your new bit of equipment before returning to the bike, walk forward and you'll see a now move-able block the last two are there.

Played through Southern Mexico nearly three times to find all treasures. Missed one in a pot in a corner of the courtyard where the entrance to Xibalba opens after solving the two riddles. I swear it was not there on the first two occasions. I hate this game.

I have had this glitch on me. An artifact just doesn't appear for me in the first mission when coming back for it in treasure hunt. I am 100% sure that I didn't just miss anything. I did 3 full run throughs consulting a video each time, assuming I was in error, but it's glitched. I fully confirmed it by making a new save file, then going by memory: I got 26/26 first try without even following the guide or doing anything new, just going right to the places I remembered. The only foolproof way to get this is to make a manual save at the start of a level, spoil yourself on locations before doing each mission, and reloading if you get to the end without all of them. At the very least, I assume the more you get on your first play, the less the chance for one to not appear in treasure hunt.