A K-1 Partner was with Reef and we do not have .

Form 1065 is the tax form a partnership files with the government and then k-1 forms are issued to the partners. Can you clarify your question since you will not get a 1065?

contact the partnership. they have until 3/15/2024 to file unextended and until 9/15/2024 to file if extended. 

Why did K-1 appear on our 2023 tax return 

Why did this appear on our 2023 tax info? It has not been on any previous filings!

They have no record for us

If a K-1 appeared in your return without your entering it, then you need to contact support.