diff --git a/src/libslic3r/Preset.cpp b/src/libslic3r/Preset.cpp
index af3bfc05e1..871cb1e3f2 100644
--- a/src/libslic3r/Preset.cpp
+++ b/src/libslic3r/Preset.cpp
@@ -2852,7 +2852,9 @@ void PresetCollection::save_current_preset(const std::string &new_name, bool det
         else if (m_type == Preset::TYPE_FILAMENT) {
             preset.config.option<ConfigOptionStrings>("filament_settings_id", true)->values[0] = new_name;
             // Generate a unique filament_id for user presets that don't have one yet (PR #13315).
-            if (preset.filament_id.empty()) {
+            // Also regenerate when a derived preset still carries an inherited vendor id
+            // (non-P), otherwise AMS sync falls back to the vendor preset (Issue #52).
+            if (preset.filament_id.empty() || preset.filament_id.front() != 'P') {
                 boost::uuids::detail::md5 hash;
                 boost::uuids::detail::md5::digest_type digest;
                 hash.process_bytes(new_name.data(), new_name.size());