Here's an interesting one.
I clicked on the "Doom" game in my Owned games list (https://www.boardgameatlas.com/game/0KCDwAG6Tg/doom). Now if you try that link, you'll see it doesn't find what it's looking for.
The actual game is found here:
My review for the doom game is attached to it but it's not on my owned list. I am thinking that maybe the name of the game was updated but it didn't update my list. I am guessing you are linking to the game via name in the URL perhaps?
I know game names don't change often but it's really vulnerable to someone going to a popular game, tweaking the name with a blank or something and then buggering everyone's links. It's why internal ID's are way better. I'm just guessing though and perhaps it's another issue.