What if the right to work check fails due to weak match?

When conducting a right to work check for an applicant using a British/Irish passport, if the face matching doesn't pass, does this mean the check needs to be repeated?

A face match may fail due to sub optimal lighting conditions but the right to work results say the document is genuine. You can collect a second piece of supporting evidence, this might be a driving license and conduct an identity fraud check (an address check). This will give you a the ability to take the M2 route to proving the identity profile.