diff --git a/src/slic3r/plugin/PluginDescriptor.hpp b/src/slic3r/plugin/PluginDescriptor.hpp
index 28c411b176..73061aefda 100644
--- a/src/slic3r/plugin/PluginDescriptor.hpp
+++ b/src/slic3r/plugin/PluginDescriptor.hpp
@@ -66,6 +66,10 @@ struct PluginDescriptor
     std::string error;                     // Blocking error message. Non-empty means the plugin is in an error state.
     std::optional<CloudPluginState> cloud; // Extra cloud state layered on top of a normal plugin descriptor.
     bool metadata_valid = false;           // Manifest/package validity stays separate from the user-facing error field.
+    // Whether the discovery pass successfully read .install_state.json. This is transient scan
+    // metadata, used to distinguish an explicit enabled=false from a sidecar that was unavailable
+    // during a live package replacement.
+    bool install_state_valid = false;
     // Package auto-load flag, read from .install_state.json. Defaults to FALSE: a package with no
     // sidecar has never been installed through Orca and carries no auto-load intent, so it must not
     // be loaded at startup. Installing a package writes the sidecar with enabled = true.
diff --git a/src/slic3r/plugin/PluginFsUtils.cpp b/src/slic3r/plugin/PluginFsUtils.cpp
index b0867ef28f..445dd00b9b 100644
--- a/src/slic3r/plugin/PluginFsUtils.cpp
+++ b/src/slic3r/plugin/PluginFsUtils.cpp
@@ -172,7 +172,7 @@ void scan_plugin_directory(const std::string& dir_path, std::vector<PluginDescri
             // its error, rather than dropping it silently.
             if (entry_path.empty()) {
                 descriptor.set_error(entry_error);
-                read_install_state(plugin_dir, descriptor);
+                descriptor.install_state_valid = read_install_state(plugin_dir, descriptor);
                 assign_discovered_plugin_key(descriptor, plugin_dir);
                 out.push_back(std::move(descriptor));
                 BOOST_LOG_TRIVIAL(warning) << "Invalid plugin package: " << plugin_dir.string() << " - " << out.back().error;
@@ -185,7 +185,7 @@ void scan_plugin_directory(const std::string& dir_path, std::vector<PluginDescri
                                               read_python_plugin_metadata(entry_path, descriptor, meta_error);
             if (!parsed) {
                 descriptor.set_error(meta_error);
-                read_install_state(plugin_dir, descriptor);
+                descriptor.install_state_valid = read_install_state(plugin_dir, descriptor);
                 assign_discovered_plugin_key(descriptor, entry_path);
                 out.push_back(std::move(descriptor));
                 BOOST_LOG_TRIVIAL(warning) << (is_wheel ? "Invalid wheel plugin: " : "Invalid .py plugin: ")
@@ -199,7 +199,7 @@ void scan_plugin_directory(const std::string& dir_path, std::vector<PluginDescri
 
             // Cloud identity and the package-level auto-load flag. plugin_key is always derived
             // below, never read from the sidecar.
-            read_install_state(plugin_dir, descriptor);
+            descriptor.install_state_valid = read_install_state(plugin_dir, descriptor);
             assign_discovered_plugin_key(descriptor, entry_path);
 
             out.push_back(std::move(descriptor));
@@ -735,11 +735,11 @@ bool extract_zip_to_directory(const boost::filesystem::path& zip_path, const boo
     return true;
 }
 
-void read_install_state(const boost::filesystem::path& plugin_dir, PluginDescriptor& entry)
+bool read_install_state(const boost::filesystem::path& plugin_dir, PluginDescriptor& entry)
 {
     PluginInstallState state;
     if (!read_install_state(plugin_dir, state))
-        return;
+        return false;
 
     // The cloud identity and the persisted installed version are read back. plugin_key
     // is always derived by the catalog scan (filename for local, the cloud uuid for
@@ -756,6 +756,7 @@ void read_install_state(const boost::filesystem::path& plugin_dir, PluginDescrip
     // capability has no existence — and so no state — until it is materialized, at which point the
     // loader seeds the flag onto the capability itself.
     entry.enabled = state.enabled;
+    return true;
 }
 
 bool read_install_state(const boost::filesystem::path& plugin_dir, PluginInstallState& out)
diff --git a/src/slic3r/plugin/PluginFsUtils.hpp b/src/slic3r/plugin/PluginFsUtils.hpp
index f65a5e0e69..7922946b1c 100644
--- a/src/slic3r/plugin/PluginFsUtils.hpp
+++ b/src/slic3r/plugin/PluginFsUtils.hpp
@@ -156,8 +156,9 @@ bool write_install_state(const boost::filesystem::path& plugin_dir, const Plugin
 // Convenience overload: write(dir, entry, /*enabled=*/true, /*capabilities=*/{}).
 bool write_install_state(const boost::filesystem::path& plugin_dir, const PluginDescriptor& entry);
 
-// Reads only the cloud identity (uuid) back into the descriptor; plugin_key is always derived.
-void read_install_state(const boost::filesystem::path& plugin_dir, PluginDescriptor& entry);
+// Reads install state back into the descriptor; plugin_key is always derived. Returns whether the
+// sidecar was present and valid.
+bool read_install_state(const boost::filesystem::path& plugin_dir, PluginDescriptor& entry);
 // Full read of the sidecar; returns false if there is no/invalid sidecar.
 bool read_install_state(const boost::filesystem::path& plugin_dir, PluginInstallState& out);
 
diff --git a/src/slic3r/plugin/PluginManager.cpp b/src/slic3r/plugin/PluginManager.cpp
index c586aafe99..761a9aad63 100644
--- a/src/slic3r/plugin/PluginManager.cpp
+++ b/src/slic3r/plugin/PluginManager.cpp
@@ -321,6 +321,8 @@ void PluginManager::merge_discovered_plugins(std::vector<PluginDescriptor> disco
 
             // A manifest-only rescan has nothing to say about capabilities, so the live module and
             // instances are left alone.
+            if (!descriptor.install_state_valid)
+                descriptor.enabled = existing->descriptor.enabled;
             existing->descriptor = std::move(descriptor);
         }