@Joheat55 I mailed my paper tax return in March and submitted non-filer form in April and several days ago I got the stimulus check. I'm sure my first tax return hasn't been processed due to COVID-19 (IRS stopped processing paper returns). According to your replies above, my paper return (the correct one) is going to be rejected? Then should I amend my tax return? I asked several CPA's opinions, they told me for now it's no need to amend just wait for how IRS would deal with this.
