Re: While I'm playing the sims 4 some furnitures are disappearing in the game mode.

@6745272  Do you have the Eco Lifestyle pack, and if so, is it possible that the Sharing is Caring neighborhood action plan is active somewhere in your world?  NPC sims can pick up the behaviors from action plans that are active in other neighborhoods or worlds, not just the current one.  And they can then steal just about anything.

If you're not sure whether this is happening, keep an eye on inactive sims to see what they do.  Active sims with the Recycle Disciple trait will also autonomously recycle objects, although I don't think inactive sims would.

If these are not the issues, did you use the MoveObjects cheat to place objects on this lot?