Under Review

Hello, I filed my taxes Feb 16 and it was  accepted.  Where’s my refund had no information.  So after a month of waiting I called the IRS, I was told me my return was under review but they couldn’t tell me why.  Simple 1040 with standard deduction.  The differences from past year tax return: I couldn’t itemize this year, and our income was lower. So my question is, according to our 2019 taxes we will not get any of the third stimulus payment, if they use our 2020 tax return, we would get the full amount-will we be able to get the third payment when our taxes are finally processed? Or are we out of luck because of a random review?