Often when people talk about Trump and Latinos they are talking about immigration policies, deportation, etc.
The majority of U.S. Latinos are at least second generation; 67% according to
this poll. Immigration, deportation, etc. is not directly their interest because they are not immigrants. The U.S. Latinos who were foreign-born are nationalized and presumably already brought their families into the country via immigration so these policies are not in their interest anymore either. This is a stronger interest for immigrants who aren't nationalized, but they cannot legally vote.
Trump has never lied about his harsh immigration policies, to the extent that he's gained with Latinos it's because they support those policies or don't care either way.