You got that backwards. Hard forks make blocks that are not considered valid by previous versions. Soft forks make blocks that are considered valid by previous

You got that backwards. Hard forks make blocks that are not considered valid by previous versions. Soft forks make blocks that are considered valid by previous versions. A soft fork does stuff like e.g. changing Bitcoin blocks to be 512KB in size. In that case, all new blocks would still be seen as valid blocks for anyone still running the old version.