Missing IRS account

For a number of years, I havebe prepared my Grandson's tax return using TurboTax.  The  2023 return was rejected due to a required 1095-A  data input that had not been done. Return was mailed and received at the Austin officc.  I  checked  for itg online and was given a status.   I looked again mid-summer, It was missing.We did not receive a refund check in the amount expected. This year's (2024) return was rejected because they could not verify hlm  due  to the Last  Year's AGI  entry not being matched. Now with numerous attempts to get  IRS help,  it appears that He has been dropped from the IRS accounts data banks.    HELP!!