Why does invalidateQueries() break mutate()'s onSuccess() sometimes, but not mutateAsync().then() ?

// userMutations.js
const useCreateUserMutation = () => {
  const queryClient = useQueryClient()
  return useMutation(resetStudentsProgress, {
    onSuccess: () => queryClient.invalidateQueries(['users', 'list']), // returns a promise to onSuccess
  })
}

// CreateUser.jsx
const createUserMutation = useCreateUserMutation()
const onSubmit = (values) => createUserMutation.mutate(values, {
  onSuccess: () => {
    window.alert('User created successfully') // <- NEVER TRIGGERS
  }
})

// userMutations.js
const useCreateUserMutation = () => {
  const queryClient = useQueryClient()
  return useMutation(resetStudentsProgress, {
    onSuccess: () => {
      queryClient.invalidateQueries(['users', 'list']) // No longer returning the promise
    },
  })
}

const onSubmit = (values) => createUserMutation.mutateAsync(values)
  .then(() => window.alert('User created successfully')) // <- WORKS!!! But why?