It wasn't Russian drone
Plenkovic said a Soviet-era Tu-141 “Strizh” reconnaissance drone flew for over 40 minutes over Hungary and six to seven minutes over Croatia before crashing. Earlier, Romanian defense authorities said the drone was in Romania’s airspace for only three minutes after crossing from Ukraine, making it hard to intercept
Military experts say Ukraine is the only known current operator of the Tu-141, which has a wingspan of nearly 4 meters (12 feet) and weighs just over 6 tons.