"¿Adónde saliste a almorzar?"
Translation:Where did you go out to lunch?
DL is taking the hard line on the difference between “ir” and “Salir” and almorzar is a verb in Spanish which means to EAT lunch. The “a” here is akin to the “a” that follows “ir” (voy a comer) where “a” is always treated like translated as “to” so it’s a perfect storm. It’s going to take a while to get DL to accept “go for lunch”. BTW new note on this page says someone had it accepted!
Maybe this is regional because either sounds fine to me.
Just to note that the la / el switch only happens when the noun's first syllable (the 'a' sound) is stressed.
Your example has an accented a and so is el águila (stressed first 'a' sound). Also El habla (the speech, a feminine noun).
But it's 'La aerolínea perdió mi equipaje'.