diff --git a/src/gui/_home.py b/src/gui/_home.py
index 5f2a279..d851bc3 100644
--- a/src/gui/_home.py
+++ b/src/gui/_home.py
@@ -250,7 +250,11 @@ def _home_page() -> None:
                     st.markdown(f"### 📄 {name}")
                     st.success(t("findings.none"))
                 else:
-                    render_findings_panel(findings, header=f"📄 {name}")
+                    render_findings_panel(
+                        findings,
+                        header=f"📄 {name}",
+                        key_namespace=name,
+                    )
 
     st.divider()
     st.caption(t("chrome.footer"))
diff --git a/src/gui/components/_legacy.py b/src/gui/components/_legacy.py
index a516306..7faa282 100644
--- a/src/gui/components/_legacy.py
+++ b/src/gui/components/_legacy.py
@@ -1374,7 +1374,12 @@ def _tool_page_slug(tool_id: str) -> str:
     return _TOOL_PAGE_PATHS.get(tool_id, "")
 
 
-def render_findings_panel(findings, *, header: str | None = None) -> None:
+def render_findings_panel(
+    findings,
+    *,
+    header: str | None = None,
+    key_namespace: str = "",
+) -> None:
     """Render a list of :class:`Finding` objects grouped by tool.
 
     Each tool gets a header with the count, an open-tool button, and a list
@@ -1427,9 +1432,20 @@ def render_findings_panel(findings, *, header: str | None = None) -> None:
                 # rendering blended into the page, making the per-tool
                 # jump non-obvious. The button triggers ``st.switch_page``
                 # so navigation is still a soft switch (no full reload).
+                #
+                # ``key_namespace`` is hashed into the widget key so the
+                # home page (which calls this once PER uploaded file)
+                # doesn't collide on the shared tool_id — two files both
+                # having Clean Text findings would otherwise produce two
+                # buttons with the same key and Streamlit refuses.
+                import hashlib as _hashlib
+                ns = _hashlib.sha1(
+                    (key_namespace or "").encode("utf-8"),
+                    usedforsecurity=False,
+                ).hexdigest()[:8]
                 if st.button(
                     _t("findings.open_tool", tool=name),
-                    key=f"_findings_open_{tool_id}",
+                    key=f"_findings_open_{tool_id}_{ns}",
                     type="primary",
                     use_container_width=False,
                 ):