Logic issue in netlogo

I am writing this condition:

if [estado] of (transmilenios with [xcor = 0.5]) = "vacio" []

And im looking at the result in netlogo and i ask the observer:

[estado] of (transmilenios with [xcor = 0.5]) answer ["vacio"]

then i ask:

[estado] of (transmilenios with [xcor = 0.5]) = "vacio"

And the answer is false.

i have a headache with this lol. can someone help me?

I have tried to usea variable estado as 0/1. same answer

Estado = "vacio"/"lleno"

i have also tried

 if [estado] of (transmilenios with [xcor = 0.5]) != "lleno"

but it happens the same when estado = "lleno"