I am trying to reduce the reads from Firestore by adding timestamps to my documents and first getting them from the cache and then only those from the database with a newer timestamp.
When I run this code, however, the documents are always retrieved from the database. The cache remains empty even though – from my understanding – the cache snapshot should have the previously retrieved documents, right?

What am I doing wrong? Why are the documents not being cached?

export const getDocs = async (query) => {
  const docsData = [];
  var snapshotDb = null;
  try {
    const snapshotCache = await getDocsFromCache(query);
    if (!snapshotCache.empty) {
      const latestTimestamp = getLatestTimestamp(snapshotCache.docs);
      snapshotCache.docs.forEach(doc => docsData.push({ id: doc.id, ...doc.data() }));
      console.log('Docs from Cache: ', snapshotCache.docs.length);
      snapshotDb = await getDocsFromServer(query, where('timestamp', ">", latestTimestamp));
      console.log('Docs from DB: ', snapshotDb.docs.length);
      snapshotDb.docs.forEach(doc => {
        if (!docsData.some(d => d.id === doc.id)) {
          docsData.push({ id: doc.id, ...doc.data() });
        }
      });
    } else {
      snapshotDb = await getDocsFromServer(query);
      console.log('Docs from DB: ', snapshotDb.docs.length);
      snapshotDb.docs.forEach(doc => docsData.push({ id: doc.id, ...doc.data() }));
    }
    
  } catch (error) {
    console.error(error);
  }
  return docsData;
};