Hello Community and hope everyone is getting through the season........

I have an Partnership client who does Graphic Design for various companies. The client files a separate return for this business on Form 1065. The client uses a third party billing service (Honeybook, Inc) where all the clients services are billed and collected through. Honeybook issued the client a 1099-K for all the billing in 2023 but the actual clients also issued the client a 1099-NEC for the services. When I added up the 1099s (1099-K and 1099-NEC) they added up to double the client's gross receipts. I explained to the client the IRS received all these 1099s which indicates their taxable income for the year. The client has proven to me that they only received the Honeybook deposits where their customers remit payment to and not from the client direct. I have never seen this before and asked the client to contact Honeybook directly to further investigate this duplication. How would I show this on the tax return if the billing company will not correct the 1099-K issued? I am presuming showing it as a contra sale? Any advice on how I should handle in the return? Thanks!