diff --git a/src/libslic3r/Print.cpp b/src/libslic3r/Print.cpp
index a335e29b82..d53a168ec2 100644
--- a/src/libslic3r/Print.cpp
+++ b/src/libslic3r/Print.cpp
@@ -1254,10 +1254,6 @@ StringObjectException Print::check_multi_filament_valid(const Print& print)
     return ret;
 }
 
-// Orca: this g92e0 regex is used copied from PrusaSlicer
-// Matches "G92 E0" with various forms of writing the zero and with an optional comment.
-boost::regex regex_g92e0 { "^[ \\t]*[gG]92[ \\t]*[eE](0(\\.0*)?|\\.0+)[ \\t]*(;.*)?$" };
-
 // Precondition: Print::validate() requires the Print::apply() to be called its invocation.
 //BBS: refine seq-print validation logic.....FIXME:StringObjectException *warning can only contain one warning, but there might be many warnings, need a vector<StringObjectException>
 StringObjectException Print::validate(StringObjectException *warning, Polygons* collison_polygons, std::vector<std::pair<Polygon, float>>* height_polygons) const
@@ -1675,26 +1671,60 @@ StringObjectException Print::validate(StringObjectException *warning, Polygons*
     }
 
     // Orca: G92 E0 is not supported when using absolute extruder addressing
-    // This check is copied from PrusaSlicer, the original author is Vojtech Bubnik
-    if(!is_BBL_printer()) {
-        bool before_layer_gcode_resets_extruder =
-            boost::regex_search(m_config.before_layer_change_gcode.value, regex_g92e0);
-        bool layer_gcode_resets_extruder = boost::regex_search(m_config.layer_change_gcode.value, regex_g92e0);
-        if (m_config.use_relative_e_distances) {
-            // See GH issues #6336 #5073
-            if ((m_config.gcode_flavor == gcfMarlinLegacy || m_config.gcode_flavor == gcfMarlinFirmware) &&
-                !before_layer_gcode_resets_extruder && !layer_gcode_resets_extruder)
-                return {L("Relative extruder addressing requires resetting the extruder position at each layer to "
-                          "prevent loss of floating point accuracy. Add \"G92 E0\" to layer_gcode."),
-                        nullptr, "before_layer_change_gcode"};
-        } else if (before_layer_gcode_resets_extruder)
-            return {L("\"G92 E0\" was found in before_layer_gcode, which is incompatible with absolute extruder "
+    // This check is modified from PrusaSlicer, the original author is Vojtech Bubnik
+    // Orca: case‑sensitive match for exactly "G92 E0" (uppercase G and E only) 
+    // because gcode is case sensitive and G92 e0 satisfies the regex but causes a slicing error
+    // https://github.com/OrcaSlicer/OrcaSlicer/issues/13927
+
+	    // Matches any case of "G92 E0" (original pattern)
+    static const boost::regex regex_g92e0 {
+        "^[ \\t]*[gG]92[ \\t]*[eE](0(\\.0*)?|\\.0+)[ \\t]*(;.*)?$"
+    };
+    // Matches only the exact uppercase "G92 E0"
+    static const boost::regex regex_g92e0_correct {
+        "^[ \\t]*G92[ \\t]*E(0(\\.0*)?|\\.0+)[ \\t]*(;.*)?$"
+    };
+
+    const bool before_has_g92_any = boost::regex_search(
+        m_config.before_layer_change_gcode.value, regex_g92e0);
+    const bool layer_has_g92_any  = boost::regex_search(
+        m_config.layer_change_gcode.value, regex_g92e0);
+
+    if (m_config.use_relative_e_distances) {
+        // Relative mode: "G92 E0" is required to reset extruder position.
+        const bool before_has_g92_exact = boost::regex_search(
+            m_config.before_layer_change_gcode.value, regex_g92e0_correct);
+        const bool layer_has_g92_exact  = boost::regex_search(
+            m_config.layer_change_gcode.value, regex_g92e0_correct);
+
+        // Wrong case found?
+        if (before_has_g92_any && !before_has_g92_exact)
+            return {L("\"G92 E0\" was found in before_layer_change_gcode, but the G or E are not uppercase. "
+                      "Please change them to the exact uppercase \"G92 E0\"."),
+                    nullptr, "before_layer_change_gcode"};
+        if (layer_has_g92_any && !layer_has_g92_exact)
+            return {L("\"G92 E0\" was found in layer_change_gcode, but the G or E are not uppercase. "
+                      "Please change them to the exact uppercase \"G92 E0\"."),
+                    nullptr, "layer_change_gcode"};
+
+        // Only Marlin flavours need the reset; BBL printers do not.
+        if ((m_config.gcode_flavor == gcfMarlinLegacy || m_config.gcode_flavor == gcfMarlinFirmware) &&
+            !is_BBL_printer() &&
+            !before_has_g92_exact && !layer_has_g92_exact)
+            return {L("Relative extruder addressing requires resetting the extruder position at each layer to "
+                      "prevent loss of floating point accuracy. Add \"G92 E0\" to layer_gcode."),
+                    nullptr, "before_layer_change_gcode"};
+    } else {
+        // Absolute mode: any occurrence of "G92 E0" is incompatible.
+        if (before_has_g92_any)
+            return {L("\"G92 E0\" was found in before_layer_change_gcode, which is incompatible with absolute extruder "
                       "addressing."),
                     nullptr, "before_layer_change_gcode"};
-        else if (layer_gcode_resets_extruder)
-            return {L("\"G92 E0\" was found in layer_gcode, which is incompatible with absolute extruder addressing."),
+        if (layer_has_g92_any)
+            return {L("\"G92 E0\" was found in layer_change_gcode, which is incompatible with absolute extruder "
+                      "addressing."),
                     nullptr, "layer_change_gcode"};
-    }
+	}
 
     const ConfigOptionDef* bed_type_def = print_config_def.get("curr_bed_type");
     assert(bed_type_def != nullptr);