If you have an business account, migration is non-trivial: It's not uncommon to have hundreds of shared folders of secrets accessible by hundreds of teams.
The meta information (which user account belongs to which team, which team has what kind of access {none,read-only,read-write} to which folder) is not trivial to migrate.
Last time I migrated (many years ago), not all the data was in the export. And the secure notes especially were mostly missing or messed up.
I think others have posted on HN that they experienced the same last year when they attempted to migtate.
So you may have exported in 10m, but do not assume you got everything, go through the list and make sure everything is there (including verifying the contents).