Sylvester Stallone and Jennifer Flavin are once again looking to unload their Hidden Hills property ... they just put it back on the market, only 3 months after pulling the original listing.
Real estate sources tell TMZ ... the famous couple's estate is now listed for $21.3 million, which is a $1.2 million price reduction.
Remember ... Sly and JF put the place up for sale back in December for $22.5 million, but it never sold, and in February they took it off the market.