I forget where I read it (probably in extra-biblical rabbinic writings) but I think it was generally thought that after Solomons temple was completed, the desert tabernacle was disassembled and stored in the temple complex, perhaps even inside the Holy of Holies.
That’s very interesting. I’d like to find out more about that. If it was indeed kept and stored, then that would lend more credibility to the Maccabees account of Jeremiah taking the Ark and hiding it.