I have just hit this same problem, unbelievably infuriating!!
I am level 29 and love the way my house looks (even if some may think it’s too cluttered - see pics), however I now have to “store” some of my beloved items in order to;
a) complete the daily task list,
b) level up my status and
c) actually fill new/empty rooms with new items
Everything was going so well until this point and I was loving this game and seeing my house improve little by little each day.
Please EA - sort this issue so that I and many others can continue expanding my Sims home 😢
I’m not sure the point in playing unless this is fixed - storing items = not the house I want!!