That is really weird.

Potential things to try:

1. Delete the 1095-A and 8962, and enter it 'fresh' again.
2. Ask the taxpayer if they would be willing to contribute (or increase) their Traditional IRA contribution to get the percentage to 399% or less (being right on 400% could be a weird spot).
3. Wait a week to file to see if it is an IRS quirk and hopefully they will fix it.

However, a note of caution about repeated e-file attempts:  If I remember correctly, if a tax return is rejected 5 times, it is permanently rejected and paper filing is the only option at that point.