From suspected CGIN to HPV related changes only?

Hi everyone, I am mega confused after just hearing from the doctor! Here’s my timeline of events:

Sept - first colposcopy, dr suspected low grade, biopsy showed CIN1 at most but transformation zone not present in sample so retest in 3 months

Dec - second colposcopy, dr suspected low grade but thought she could possibly see some moderate grade in cervical canal. Biopsy has just come back as no CIN or CGIN, just HPV related changes and transformation zone was present

How can this be??? If the dr could SEE changes inside the canal, how can the biopsy just be HPV related changes? Can HPV related changes look like CIN? And can they be in the canal? Do I need a second opinion???