@ellimist
It did get accepted eventually, but I had to go through their steps. It's nothing crazy though.
The IRS sent me a letter saying they needed more information about my claim. The letter tells you what to send/fax back.
I replied back faxing the information they requested (a copy of the IRS letter they sent me, my W2, my schedule 3) along with a brief "response" letter summarizing the issue - how "the total Social Security tax withheld for the year exceeds the maximum limit due to my earnings from multiple employers managed through a Certified PEO". Honestly, I just put all the information in ChatGPT and had it write the response letter for me.
I also included in the fax a letter from the PEO stating their position and how I'm supposed take a credit on line 31 on the 1040 (they've done this before so they knew everything to put in their letter, citing the appropriate IRS rules etc).
It took about a month after faxing the file (probably because it was during the heavy tax time in april), but they did accept everything and I got the excess amount properly credited and the right refund.
