Patch up M290, M851

Marlin/src/core/language.h

 #define MSG_Z2_MIN                          "z2_min: "
 #define MSG_Z2_MAX                          "z2_max: "
 #define MSG_Z_PROBE                         "z_probe: "
+#define MSG_PROBE_Z_OFFSET                  "Probe Z Offset"
 #define MSG_FILAMENT_RUNOUT_SENSOR          "filament: "
 #define MSG_ERR_MATERIAL_INDEX              "M145 S<index> out of range (0-1)"
 #define MSG_ERR_M355_NONE                   "No case light"

Marlin/src/gcode/motion/M290.cpp

 #include "../../module/temperature.h"
 #include "../../module/planner.h"
 
+#if ENABLED(BABYSTEP_ZPROBE_OFFSET)
+  #include "../../core/serial.h"
+#endif
+
 /**
  * M290: Babystepping
  */
         const float offs = constrain(parser.value_axis_units((AxisEnum)a), -2, 2);
         thermalManager.babystep_axis((AxisEnum)a, offs * planner.axis_steps_per_mm[a]);
         #if ENABLED(BABYSTEP_ZPROBE_OFFSET)
-          zprobe_zoffset += offs;
+          if (a == Z_AXIS) zprobe_zoffset += offs;
         #endif
       }
   #else
       #endif
     }
   #endif
+  #if ENABLED(BABYSTEP_ZPROBE_OFFSET)
+    SERIAL_ECHO_START();
+    SERIAL_ECHOLNPAIR(MSG_PROBE_Z_OFFSET ": ", zprobe_zoffset);
+  #endif
 }
 
 #endif // BABYSTEPPING

Marlin/src/gcode/probe/M851.cpp

 
 void GcodeSuite::M851() {
   SERIAL_ECHO_START();
-  SERIAL_ECHOPGM(MSG_ZPROBE_ZOFFSET " ");
+  SERIAL_ECHOPGM(MSG_PROBE_Z_OFFSET);
   if (parser.seen('Z')) {
     const float value = parser.value_linear_units();
-    if (WITHIN(value, Z_PROBE_OFFSET_RANGE_MIN, Z_PROBE_OFFSET_RANGE_MAX)) {
-      zprobe_zoffset = value;
-      SERIAL_ECHO(zprobe_zoffset);
+    if (!WITHIN(value, Z_PROBE_OFFSET_RANGE_MIN, Z_PROBE_OFFSET_RANGE_MAX)) {
+      SERIAL_ECHOLNPGM(" " MSG_Z_MIN " " STRINGIFY(Z_PROBE_OFFSET_RANGE_MIN) " " MSG_Z_MAX " " STRINGIFY(Z_PROBE_OFFSET_RANGE_MAX));
+      return;
     }
-    else
-      SERIAL_ECHOPGM(MSG_Z_MIN " " STRINGIFY(Z_PROBE_OFFSET_RANGE_MIN) " " MSG_Z_MAX " " STRINGIFY(Z_PROBE_OFFSET_RANGE_MAX));
+    zprobe_zoffset = value;
   }
-  else
-    SERIAL_ECHOPAIR(": ", zprobe_zoffset);
-
-  SERIAL_EOL();
+  SERIAL_ECHOLNPAIR(": ", zprobe_zoffset);
 }
 
 #endif // HAS_BED_PROBE