diff --git a/src/slic3r/Utils/MoonrakerPrinterAgent.cpp b/src/slic3r/Utils/MoonrakerPrinterAgent.cpp
index f33886b3c5e..049c6f46892 100644
--- a/src/slic3r/Utils/MoonrakerPrinterAgent.cpp
+++ b/src/slic3r/Utils/MoonrakerPrinterAgent.cpp
@@ -193,7 +193,13 @@ std::string filament_id_by_name(const Slic3r::PresetCollection& filaments,
                                      << " filament_id_empty=" << preset.filament_id.empty();
             continue;
         }
-        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) {