diff --git a/LightlessSync/UI/LightFinderUI.cs b/LightlessSync/UI/LightFinderUI.cs
index e41d17d..09ba646 100644
--- a/LightlessSync/UI/LightFinderUI.cs
+++ b/LightlessSync/UI/LightFinderUI.cs
@@ -497,7 +497,7 @@ public class LightFinderUI : WindowMediatorSubscriberBase
 
         var cardData = new List<(GroupJoinDto Shell, string BroadcasterName, bool IsOwnBroadcast)>();
 
-        foreach (var shell in _nearbySyncshells)
+        foreach (var shell in _nearbySyncshells.ToArray())
         {
             if (shell?.Group == null || string.IsNullOrEmpty(shell.Group.GID))
                 continue;
@@ -1566,11 +1566,20 @@ public class LightFinderUI : WindowMediatorSubscriberBase
 
         if (previousGid != null)
         {
-            var newIndex = _nearbySyncshells.FindIndex(s => string.Equals(s.Group.GID, previousGid, StringComparison.Ordinal));
-            if (newIndex >= 0)
+            try
             {
-                _selectedNearbyIndex = newIndex;
-                return;
+                var nearbySyncshellsSnapshot = _nearbySyncshells.ToArray();
+                var newIndex = Array.FindIndex(nearbySyncshellsSnapshot,
+                    s => string.Equals(s.Group.GID, previousGid, StringComparison.Ordinal));
+                if (newIndex >= 0)
+                {
+                    _selectedNearbyIndex = newIndex;
+                    return;
+                }
+            }
+            catch
+            {
+                ClearSelection();
             }
         }
 
@@ -1612,9 +1621,18 @@ public class LightFinderUI : WindowMediatorSubscriberBase
 
     private string? GetSelectedGid()
     {
-        if (_selectedNearbyIndex < 0 || _selectedNearbyIndex >= _nearbySyncshells.Count)
+        try
+        {
+            var index = _selectedNearbyIndex;
+            var list = _nearbySyncshells.ToArray();
+            if (index < 0 || index >= list.Length)
+                return null;
+            return list[index].Group.GID;
+        }
+        catch
+        {
             return null;
-        return _nearbySyncshells[_selectedNearbyIndex].Group.GID;
+        }
     }
 
     #endregion