diff --git a/src/slic3r/Utils/MoonrakerPrinterAgent.cpp b/src/slic3r/Utils/MoonrakerPrinterAgent.cpp
index 6ff593a16ec..ffa278b04ae 100644
--- a/src/slic3r/Utils/MoonrakerPrinterAgent.cpp
+++ b/src/slic3r/Utils/MoonrakerPrinterAgent.cpp
@@ -203,7 +203,13 @@ std::string filament_id_by_name(const Slic3r::PresetCollection& filaments,
             if (pass == 1 && !preset.is_compatible) {
                 continue; // Pass 1: only compatible presets
             }
-            if (!normalized_vendor_filters.empty()) {
+            // Skip the vendor filter for user presets: a preset derived from a
+            // vendor-specific parent (e.g. "Anycubic PLA Matte @...") resolves
+            // filament_vendor from the PARENT ("Anycubic"), not from the user
+            // preset itself ("Tinmorry"), so the filter would wrongly drop it
+            // and the AMS sync falls back to the vendor preset (Issue #52). The
+            // strict name match below is discriminating enough for user presets.
+            if (!preset.is_user() && !normalized_vendor_filters.empty()) {
                 const std::string preset_vendor = normalize_filament_name_for_match(preset.config.opt_string("filament_vendor", 0u));
                 bool vendor_match = false;
                 for (const auto& vendor_filter : normalized_vendor_filters) {