diff --git a/CHANGELOG.md b/CHANGELOG.md
index cd91e4979a..b061046442 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,9 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 ### Added
 - Support `marginal_x`/`marginal_y="heatmap"` in `density_heatmap`, drawing a single-row/column heatmap strip in the margin colored by the same `z`/`histfunc` aggregate as the main plot and sharing its color scale [[#5706](https://github.com/plotly/plotly.py/issues/5706)], with thanks to @lucasjamar for the contribution!
 
+### Fixed
+- Fix `FigureWidget` state synchronization bug where frontend modifications to array properties (like `layout.shapes`) failed to properly update the Python property cache and occasionally surfaced `Undefined` objects [[#5689](https://github.com/plotly/plotly.py/issues/5689)]
+
 ## [7.0.0] - 2026-08-25
 
 ### Fixed
diff --git a/plotly/basedatatypes.py b/plotly/basedatatypes.py
index d81ba0950c..121ae52b73 100644
--- a/plotly/basedatatypes.py
+++ b/plotly/basedatatypes.py
@@ -5458,6 +5458,16 @@ def _dispatch_change_callbacks(self, changed_paths):
         -------
         None
         """
+        # Invalidate cache for changed compound array properties so that they are 
+        # reconstructed from the underlying properties dictionary on the next access.
+        # We only pop from _compound_array_props because compound arrays are immutable 
+        # tuples that must be rebuilt to reflect added or removed elements.
+        for path in changed_paths:
+            if len(path) > 0:
+                prop = path[0]
+                if prop in self._compound_array_props:
+                    self._compound_array_props.pop(prop, None)
+
         # Loop over registered callbacks
         # ------------------------------
         for prop_path_tuples, callbacks in self._change_callbacks.items():