I'm trying to book roundtrip flights (or one-ways) on Delta from SMF to CUZ (Cusco, Peru) via LAX and LIM, with the last two segments operated by LATAM. The flight to CUZ on 5/9/24 is not a problem, but on the return, specifically on 5/19/24, the only morning departure shown is the 655am from Cuzco, even though there are also LATAM flights to LIM departing at 550am, 800am, and 835am, all of which would nicely connect with the 12 Noon LATAM flight to LAX. I would prefer either the 800am or 835am flights, but am puzzled how I might book those if they are not shown. Would calling Delta be the solution here?

Alternatively, I looked at booking on the LATAM site, but it refuses to recognize SMF as a served destination. It of course shows LAX as a destination, and offers the later flights at 800 and 835 as connections. It seems a bit odd that LATAM would not show the connection to SMF via its partner Delta.

What is the best approach to proceed here? Thanks in advance for any assistance.