You can pass objects by reference to ember data queries, so you can so something like...

this.store.loadRecords('post', { filter: { slugs: ['post-1', 'post-2'] } })

and the backend is going to get an array of slugs that it can use to filter

there's an issue where if storefront gets a mutable array, that array can be mutated, and internally change so the query ends up not reflecting the data

this.store.loadRecords('post', { filter: { slugs: this.queryParams.slugs } })

now as slugs get added and removed from some controller action, that same array is used in the query.

The fix here is to copy/clone reference objects that are passed to storefront.