Open minecraft, go to market place, click on search button, type in "LittleBigPlanet" or "Little Big Planet", mashup pack does not appear in search results.

if you own the mashup pack, the Little Big Planet Mashup does not appear in your owned inventory section under any category.

the only way to retrieve the Little Big Planet mashup pack is to web search it and click the link to go to the pack on the Minecraft.net web page, click purchase, then Minecraft will launch and load the marketplace page for Little Big Planet Mashup pack, If you own it, you can just download it, or if you don't, you can purchase, but purchase does not show up in owned packs.

this happens on every version including Android, Windows 10, PS4/PS5.

on PS4 or PS5, if you purchased the Starter pack which includes the Little Big Planet mashup, you have to install from the PS Store on console, then let game update the pack when you select the textures or world to play.

expected results: Little big Planet mashup to be available in search of mashups on Minecraft Store, and the purchased pack should appear in your Purchased Mashups listing under your owned section of the Minecraft Store without having to use the PS Store or a web page in order to access the mashup pack.

The Little Big Planet mashup pack does not show up in store by searching Mojang or 4J Studios either.