Apollo-boost caching issue - angular6

Question

I'm experiencing an issue with apollo client caching, and I'm not sure I understand why. I'm building an angular 6 app, using apollo-boost, all is working well. I have a scenario now where my a graphql query takes an id (of a user) and a filter string (used to filter records on the backend). The angular component code looks like:
ngOnInit() {
this.filter$.subscribe(filterValue => {
this.route.params.subscribe(this.getAppointments.bind(this, filterValue));
});
}
The getAppointments function looks like:
getAppointments(filter: string, params: {id: string}) {
this.artistAppointmentBookGQL.watch({artistId: user.artist._id, filter}).valueChanges
.pipe(
map(results => {
// THIS ALWAYS RUNS WHEN THE FILTER CHANGES
// HOWEVER THE RESULTS ARE ALWAYS THE LAST QUERY RUN
// IF THE FILTER HAS BEEN RUN BEFORE
console.log(user.artist._id, filter, results.data.artist.appointmentBook);
return results.data.artist.appointmentBook;
}));
}
The graphql query:
query artistAppointmentBook($artistId: ID!, $filter: String) {
artist(id: $artistId, appointmentType: $filter) {
_id
appointmentBook {
_id
created_at
firstName
lastName
date
price
stripe {
charge {
id
amount
}
}
}
}
The main issue:
I have 4 different possible filter values (all, unconfirmed, confirmed, paid). When I run these queries with each filter value, it works as expected, and I get back the proper result sets from the apollo server. However, as soon as I run the same query twice, I only get back the result of whatever the last query was, and no network call is made, presumably because it's using a cached version.
Shouldn't the cache be based on the variable inputs? It seems to run fine the first time I run with different variables, but as soon as one gets duplicated I only get back whatever the last call yielded. Thanks for any help!
This gif demonstrates the issue:

Answer 1

Figured out my issue. As it should, apollo is caching the artist record because it has an _id and a type. The filter was being passed into artist query, when it should have been passed in at the appointmentBook level. I updated my schema to accept the filter param and then passed it in there instead of into the artist query.
Originally I had:
query artistAppointmentBook($artistId: ID!, $filter: String) {
artist(id: $artistId, appointmentType: $filter) {
_id
appointmentBook {
_id
created_at
firstName
lastName
date
price
stripe {
charge {
id
amount
}
}
}
}
Which needed to be changed to:
query artistAppointmentBook($artistId: ID!, $filter: String) {
artist(id: $artistId) {
_id
appointmentBook(filter: $filter) {
_id
created_at
firstName
lastName
date
price
stripe {
charge {
id
amount
}
}
}
}
After this update, the queries are cached properly.