Warranty Diagnostic Service?

I was told from a service manager that the car lot specifically does not make money from toyota for diagnostic services.

Is this true?

I was recently denied a diagnostic warranty service or appointment on a 2025 Toyota still under warranty. I understand some lots don’t like to touch a car that is from another lot. However it’s a sister lot and they happen to have the same car on hand so there is no excuses and issues finding the car to compare it to.

What good is warranty if they won’t diagnose or repair concerns, issues, defects or problems.