diff --git a/.gitignore b/.gitignore
index 109efbe..671e79f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,9 +1,10 @@
 build/
 .DS_STORE
+.vscode/
 .idea/
 *.iml
 /nbcode/l10n/locale_ja/release/
 /nbcode/l10n/locale_zh_CN/release/
 /nbcode/l10n/locale_ja/nbproject/private/
 /nbcode/l10n/locale_zh_CN/nbproject/private/
-telemetryConfig.json
\ No newline at end of file
+telemetryConfig.json
diff --git a/nbcode/telemetry/src/org/netbeans/modules/nbcode/java/lsp/server/telemetry/SourceFeatureCache.java b/nbcode/telemetry/src/org/netbeans/modules/nbcode/java/lsp/server/telemetry/SourceFeatureCache.java
index 31e392e..6b1c5b2 100644
--- a/nbcode/telemetry/src/org/netbeans/modules/nbcode/java/lsp/server/telemetry/SourceFeatureCache.java
+++ b/nbcode/telemetry/src/org/netbeans/modules/nbcode/java/lsp/server/telemetry/SourceFeatureCache.java
@@ -61,8 +61,7 @@ public boolean isPreviewEnabled(SourceInfo sourceInfo) {
     }
 
     private static class Singleton {
-
-        private static final int CACHE_EXPIRY = Math.max(0, NbPreferences.forModule(JavaLangFeaturesTelemetryProvider.class).node(JavaLangFeaturesTelemetryProvider.PREFERENCES_NODE).getInt(JavaLangFeaturesTelemetryProvider.PREFERENCES_KEY_CACHE_EXPIRY, 3_600_000)); // 1 hour
+        private static final int CACHE_EXPIRY = Math.max(0, NbPreferences.forModule(JavaLangFeaturesTelemetryProvider.class).node(JavaLangFeaturesTelemetryProvider.PREFERENCES_NODE).getInt(JavaLangFeaturesTelemetryProvider.PREFERENCES_KEY_CACHE_EXPIRY, 12 * 3_600_000)); // 12 hours
         private static final ConcurrentHashMap<String, SourceFeatureCacheEntry> cachedSourceFeatures = new ConcurrentHashMap<>();
     }
 
@@ -77,8 +76,12 @@ public static SourceFeatureCacheEntry get(String sourceName) {
     public static boolean add(String sourceName, Set<String> features) {
         final Set<String> newFeatures = Collections.unmodifiableSet(features);
         final SourceFeatureCacheEntry entry = getCachedSourceFeatures().compute(sourceName,
-                (name, cache) -> cache != null && cache.getFeaturesUsed().containsAll(newFeatures) ? cache
-                : new SourceFeatureCacheEntry(System.currentTimeMillis(), newFeatures, cache));
+                (name, cache) -> {
+                    if (cache != null && cache.getFeaturesUsed().containsAll(newFeatures)) return cache;
+                    if (cache != null) features.addAll(cache.getFeaturesUsed());
+                    return new SourceFeatureCacheEntry(System.currentTimeMillis(), newFeatures, cache);
+                }
+        );
 
         boolean added = newFeatures == entry.getFeaturesUsed();
         if (!added) {