Which decades are you talking about? Finland was part of the Russian Empire between 1809 and 1917, but hasn’t been invaded since — although Stalin gave it a good shot.
Invaded twice, but not occupied. Indeed, I believe Helsinki and London were the only capitals of non-neutral European countries that were not occupied during the WW2.
Finland was definitely invaded. While the Finns are often considered the victors in the Winter War because they managed to maintain their independence in spite of Stalin’s onslaught, they nonetheless lost a considerable slice of Karelia to the Soviet Union.