Investors & landlords

I guess it makes sense to start with AGI of zero for 2019 for this 2020 efile...

does the following note from IRS in February 2021 imply anything different makes sense:

CP05

Message about your 2019 tax return

We're holding your refund until we finish reviewing your return.

 

Is the message I am getting from this message board that reviewing the return from IRS and the input into their computer system occur in that order rather than inputting than reviewing?