You can block falling blocks (excluding anvils and dripstone) with a shield
Steps to Reproduce:
1) RunĀ
/summon falling_block ~ ~20 ~ {BlockState:{Name:"minecraft:tnt"},Time:1,HurtEntities:1b,FallHurtMax:40,FallDistance:80f,FallHurtAmount:2f}
2) Look at the floor where the falling block will land and block