I haven't received e-file acknowledgement from IRS after 48hours

I have a client who I e-filed his 2019 tax return two days ago, but I still did not receive the e-file acknowledgement from IRS. Actually, his tax return was rejected first time due to the code, F1040-071-05. This client is working overseas and claiming Foreign Earned Income Exclusion, so he was able to get back all his tax withheld. Because he was my prior client and the tax return was almost the same as last year and it was also never rejected for past years, I just re-transmitted his tax return without correcting anything. Since then, I have still not received any response back from the IRS. Every time when I click "Update EF status" for this client, it just shows "Return Sent to the IRS" and it has been 2 days. I just want to get IRS's response even if the tax return got rejected again.

PS: I had no problem e-filing other clients' 2019 tax returns. They are all accepted by IRS without any error.