This is BenT9 - I misunderstood your question. My guess is that you meant to say you were rejected due to an error where your AGI entered does not agree with your 2018 W-2. If this is the case my answer is not applicable to your question so please ignore it.
As noted in the other response Your 2018 AGI is obtained form your 2018 tax return which summarizes all of the income that you entered on that return not just W-2s. If you are trying to get your 2018 from your 2018 W-2s it won't work if you had any other income (for example: interest, dividends, and so on) or any other adjustment.
