Despite being a puppet and ravaged by war how much protest was there from the people and the new government, with Stalin taking Carpathian Ruthenia from Czechoslovakia? Did Czechoslovakia even want it back?
The Czechoslovak government can't be considered a puppet of the Soviet Union after World War II, but they were neither able nor particularly inclined to protest the Soviet takeover of Subcarpathian Ruthenia. The Czechoslovaks and Soviets initially agreed that the region would be returned to Czechoslovakia, but Stalin considered it strategically important and the Soviets essentially started incorporating it into the USSR as soon as the Red Army got there. This happened at the end of 1944, while Czechoslovak politicians were preoccupied with matters they considered more important. This very poor and very far-from-Prague region wasn't a priority for them. On the other hand, good relations with the Soviet Union absolutely were a priority -- both Communist and non-Communist politicians considered alliance with the Soviet Union to be essential to Czechoslovakia's postwar integrity and security.
I haven't seen any indication that the Czech population cared much about Subcarpathian Ruthenia after the Second World War, although I can't speak for the Slovaks.