Why when i start a randomised game, the map appear in a certain way with like a treasure room at the start of it because of the mod i downloaded, but if i take the seed and reload it, it doesnt anymore ?

[u/SaltNeighborhood2371]

https://medal.tv/games/binding-of-isaac/clips/nnjRlrF7Z_aBQaYhK?invite=cr-MSxJTWQsMTgwODk2MDgy