Make sure MBL starts close to the bed

Fix #10390

Marlin/Marlin_main.cpp

@@ -4277,6 +4277,12 @@ void home_all_axes() { gcode_G28(true); }
             soft_endstops_enabled = false;
           #endif
 
+          // Move close to the bed for the first point
+          if (!mbl_probe_index) {
+            current_position[Z_AXIS] = Z_MIN_POS;
+            buffer_line_to_current_position();
+          }
+
           mbl_probe_index++;
         }
         else {