Isn't it reassuring to know that in these trying times, with millions of 2019 returns not yet processed, IRS is still staying afloat with its CP-2000 operation to pester taxpayers and practitioners during tax season with notices generated by archaic computers?  Yes, I would send them a couple paragraphs explaining that it was reported on a corporation return.  I wouldn't send the complete 1120, maybe just the first page.  If your request to the payer for a corrected 1099 was made in writing, send a copy of that also.  If it wasn't, now you know for next time.