diff --git a/mobile/lib/shared/push/push_subscription.dart b/mobile/lib/shared/push/push_subscription.dart
index 761984b20b..788a1d3ab2 100644
--- a/mobile/lib/shared/push/push_subscription.dart
+++ b/mobile/lib/shared/push/push_subscription.dart
@@ -458,9 +458,12 @@ List<BuzzPushSubscription> buildDesiredBuzzPushSubscriptions({
   }
 
   final normalizedChannelIds = channelIds.map(_normalizeChannelID).toSet();
-  final normalizedMuted = mutedChannelIds.map(_normalizeChannelID).toSet();
-  final activeMuted =
-      normalizedMuted.intersection(normalizedChannelIds).toList()..sort();
+  // Mutes sync across every community and channel type, so only mutes of
+  // subscribed channels matter here; others need not fit the push grammar.
+  final activeMuted = {
+    for (final id in mutedChannelIds)
+      if (normalizedChannelIds.contains(id.toLowerCase())) id.toLowerCase(),
+  }.toList()..sort();
   final mutedIgnoreFilters = <BuzzPushFilter>[];
   for (final chunk in _chunks(activeMuted, buzzPushChannelChunkSize)) {
     mutedIgnoreFilters.add(
@@ -491,7 +494,7 @@ List<BuzzPushSubscription> buildDesiredBuzzPushSubscriptions({
     ),
   ];
 
-  final channels = normalizedChannelIds.difference(normalizedMuted).toList()
+  final channels = normalizedChannelIds.difference(activeMuted.toSet()).toList()
     ..sort();
   for (final chunk in _chunks(channels, buzzPushChannelChunkSize)) {
     subscriptions.add(
diff --git a/mobile/test/shared/push/push_subscription_test.dart b/mobile/test/shared/push/push_subscription_test.dart
index bd2bf53d93..079f2739e0 100644
--- a/mobile/test/shared/push/push_subscription_test.dart
+++ b/mobile/test/shared/push/push_subscription_test.dart
@@ -143,6 +143,21 @@ void main() {
     );
   });
 
+  test('ignores mutes outside the push channel grammar', () {
+    // Starter channels use UUIDv5 IDs; muting one must not break push setup.
+    const starterChannel = 'fee88e92-da9f-5958-a910-48db3264ad38';
+
+    final subscriptions = buildDesiredBuzzPushSubscriptions(
+      myPubkey: me,
+      channelIds: [channelA],
+      mutedChannelIds: [starterChannel, 'not-a-channel'],
+    );
+
+    expect(subscriptions, hasLength(2));
+    expect(subscriptions.first.ignore, hasLength(1));
+    expect(subscriptions.last.filter.hTags, [channelA]);
+  });
+
   test('chunks channel subscriptions to relay limits deterministically', () {
     final channels = [
       for (var i = 0; i < 51; i++)