If a dropper is facing towards a chest which can't be opened by the player (block directly above it) the items aren't getting pushed into the chest, they will be dropped
If a dropper is facing towards a chest which can't be opened by the player (block directly above it) the items aren't getting pushed into the chest, they will be dropped
If a chest is blocked, the game considers it unopenable which means unusable to machines as well as players. Hoppers won't put items into chests, comparators won't read the chest contents, etc.