Initially, when Delta made the compensation offer that later on they backed out of, they stated:
Your correspondence has been forwarded to me for further review and assistance. I apologize that you were unable to travel as planned from Lisbon with KLM via Amsterdam on October 29, 2020. I realize how frustrating this must have been having your travel plans changed unexpectedly and arriving much later than planned in the U.S. It's certainly not the experience we wanted you to have.
I've reviewed your reservation information in both the Delta and KLM reservation systems. Your ticket was purchased from Chase Travel on October 18, 2020. Upon review, KLM did have your ticket number in their reservation system prior to travel. I can not speak for if their airport computer system had the ticket number when you arrived. Nonetheless, it was not a Delta issue, nor an issue with your agency. As a courtesy, I will issue you EU 261/2004 Regulated compensation in the amount of $699.36 USD equivalent to 600 EUR. Could you please reply back to this email to confirm your address with me so there is no delay with our check payment to you.
I believe Cadee had spoken with you earlier about also sending you $25.00 USD for meals while delayed from Lisbon that day. I can include this with your compensation payment.
We truly appreciate your SkyMiles loyalty and support. I look forward to hearing from you at your earliest convenience.
There's Chase Travel, Delta, KLM as well as myself, the passenger in this story. I was there on time attempting to check-in. If Delta claims they are not at fault nor is the TA, then they are blaming this on KLM despite not being blunt about it.