1) The IRS letter you attached contains two SSNs so you should probably remove that attachment ASAP.  One starts 559 and the other 526.  There aren't names to go with them so at least that's something.

2) Wow, yay, the IRS added a bunch of lines to the 1040 and nobody bothered to tell their computer what to do with them.  I'm guessing this is a corrective distribution of an excess elective deferral.  If so, then it does count as wages and goes on the shiny new line 1h.  Presumably so the IRS can easily find it and match it to the 1099-R.  Or . . . I guess maybe not!

3) I'm not great with the letter numbers.  Is the CP2057 a "soft" letter?  I know the CP2000s have a "response" page you can fill out if you disagree and mail back to them politely telling them to go pound sand (a.k.a. "Please see line 1h of the tax return as originally filed."  You might pull a transcript.  1h was brand new last year so no guarantees that everybody got the programming right, could be that never made it into the IRS system.  If it's there, plain as day, I might include a copy of the transcript in the envelope with the response and tack on "as shown on the attached transcript."  In a perfect world you might get this fixed with a simple phone call to PPS.  I'm not sure that's the world we live in.

I have one of these from last year but it should be coming on a 2023 with a code P.  Guess I'll find out in a couple months how well that went!  Drake software was kind enough to write "EXCESS DEFERRAL" on the dotted line for 1h so maybe that will help (but probably not).

Good luck.  Please report back if/when you get any traction on this.

Rick