How could the nonconformities found in the internal audit exposed in the corrective actions affect the external audit?
What happens is that in the organization where I am, they are afraid that we will find majors or minors nonconformities, because they think that the external audit will be based on these results so they prefer just use nonconformities in general and do not use major or minor non conformities in the form.
Nonconformities found in the internal audit only will become a problem in the external audit if they are not solved as planned (i.e., actions related to them are not performed or are delayed without proper justification), or if there is a recurrence of the same nonconformity (this may mean that the root causes were not eliminated). In case they are solved as planned and there are no recurrences they will not mean a problem in the external audit.
Please note that ISO 27001 does not require non-conformities in internal audits to be classified. Normally non-conformities are classified during surveillance/certification audits.