my query on subcollection in firestore does not return any data

I have a subcollection in a document on firestore, I can get all the documents in the subcollection if I do not put any condition in the query. This snipped works

 let q = query(collection(this.firestore,`providers/${providerKey}/locations`))
 onSnapshot(q, snapshot=>callback(snapshot))

if I put any condition:

let q = query(collection(this.firestore,`providers/${providerKey}/locations`))
q = query(q, where("status","!=","DELETED")
onSnapshot(q,snapshot=>callback(snapshot)
     onSnapshot(q, snapshot=>{callback(snapshot)}

I do not get any documents all the document in the subcollection has the field status, that is a string and in it I have documents with status ACTIVE and DELETED, but nothing is found, for sure is my mistake, but I do not understand what is wrong