diff --git a/lldb/source/Plugins/Language/CPlusPlus/LibCxx.cpp b/lldb/source/Plugins/Language/CPlusPlus/LibCxx.cpp
--- a/lldb/source/Plugins/Language/CPlusPlus/LibCxx.cpp
+++ b/lldb/source/Plugins/Language/CPlusPlus/LibCxx.cpp
@@ -624,11 +624,17 @@
     ValueObjectSP short_sp(dataval_sp->GetChildAtIndex(1, true));
     if (!short_sp)
       return {};
-    ValueObjectSP location_sp = short_sp->GetChildAtIndex(
+
+    // After D128285, we need to access the size from a packed anonymous struct
+    ValueObjectSP packed_fields_sp = short_sp->GetChildAtIndex(0, true);
+    if (!packed_fields_sp)
+      return {};
+
+    ValueObjectSP location_sp = packed_fields_sp->GetChildAtIndex(
         (layout == eLibcxxStringLayoutModeDSC) ? 0 : 1, true);
     // After D125496, there is a flat layout.
     if (location_sp->GetName() == g_size_name)
-      location_sp = short_sp->GetChildAtIndex(3, true);
+      location_sp = short_sp->GetChildAtIndex(2, true);
     if (using_bitmasks)
       size = (layout == eLibcxxStringLayoutModeDSC)
                  ? size_mode_value