IRS Rejected 2019 e-file; AGI is correct, but I just mailed in 2018

I just e-filed yesterday, but IRS and California FTB rejected because my last year's AGI doesn't match their records.  I checked;  it is correct.  But I suspect they have not even processed my 2018 return yet, because it was mailed just ten days ago.  

 

I specifically did this so that the IRS would have my bank info on file for the stimulus check, which we will desperately need very soon.  How can I be sure that my 2018 paper return has been filed, so I can re-efile 2019 and it will match their records?

 

Thanks.  Stay safe.