Google Flights or Delta.com?
 

Apologies if this question has an obvious answer or if it needs to be moved to another forum (Mods please go ahead).
Booking MAD – JFK – MAD for dates in May, I pull up Delta’s website where it offers me only flights with stops (normally this is CDG or AMS) when I offer to pay with miles or (separate search) with money.
I search the same flights on Google/flights, find Delta, click through, and it offers me non-stops for the same price.
Is this normal? If both Delta and Google offer me only flights with stops, is it worthwhile to try other OTAs to see if I can get the non-stop?
Thanks!