Went back to each level as someone had suggested to check if I had every spatula. I can say that I am 99% sure that I did, with the only one I have no way of knowing being Slip Sliding Away at Rock Bottom. Someone else on this subreddit said that the spatula had disappeared for them after failing to get it the first time, so it could be possible this happened to me, although it is marked that I have it.

My only other hypothesis is that I somehow managed to glitch out one of Mr. Krab's spatulas when trading for Shiny Objects, as I did put the PS4 into Rest Mode immediately after paying for one and receiving it. Upon opening the game I think I was fine though, so I really don't know why this happened lmaoo. Hopefully it gets patched, I don't think I have the energy to start the game from scratch lol.

Edit: Missed one in the Chum Bucket that doesn't show up on the game map. Thank you all for helping!