offworld trading company problem with buying core game

oke so im new to this forum but i didnt get any replies in the steam discussion section so here i am

what is the problem: if i want to play singleplayer i need to buy the core game, if i want to buy the core game it tells me i already own it and wont receive a copy

if i look into the steam dlc it tells me i own the core game upgrade, but i am still able to buy the core game upgrade, and i would be willing to buy the upgrade  from free multiplayer edition but its not on sale

also the upgrade from free multiplayer edition doesnt show up at all in the store page only when i use the steam help section to find it for some reason

this is all extremely confusing and im not sure what is going on

pls help me in this regard

ps. i hope i didnt break any rules btw