Based on my experience this year, I would indicate that the client did receive all of the EIP1 and EIP2 and IRS will correct the return and send what is due to them. I had several clients SWEAR that they did not receive the full amount and all of them got lovely letters and all of them were wrong. I experienced IRS doing a good job. (I know, hard to believe - but true.)
Here's wishing you many Happy Returns
Have your client make their Online account with the IRS; now they can use it to get their Tax Account Transcript, which includes all of the EIP (stimulus advances) for them to provide to you.
Hold them responsible.
"Level Up" is a gaming function, not a real life function.