diff --git a/freeink-sdk b/freeink-sdk
index 9d92cb19..f611d71d 160000
--- a/freeink-sdk
+++ b/freeink-sdk
@@ -1 +1 @@
-Subproject commit 9d92cb19a8e5f1f0da8160404cc5d5f77bb9e833
+Subproject commit f611d71d8e860bb4ae50246e2e18b7985e1719ea
diff --git a/src/activities/boot_sleep/SleepActivity.cpp b/src/activities/boot_sleep/SleepActivity.cpp
index fb6c188b..e7ff4317 100644
--- a/src/activities/boot_sleep/SleepActivity.cpp
+++ b/src/activities/boot_sleep/SleepActivity.cpp
@@ -163,7 +163,7 @@ void SleepActivity::renderDefaultSleepScreen() const {
     renderer.invertScreen();
   }
 
-  renderer.displayBuffer(HalDisplay::HALF_REFRESH);
+  renderer.displayBuffer(HalDisplay::FULL_REFRESH);
 }
 
 void SleepActivity::renderBitmapSleepScreen(const Bitmap& bitmap) const {
@@ -219,13 +219,11 @@ void SleepActivity::renderBitmapSleepScreen(const Bitmap& bitmap) const {
   }
 
   if (hasGreyscale) {
-    // OEM grayscale pipeline base: on X3 this displays the frame with the
-    // dedicated "AA-pre-BW(mid)" differential waveform, leaving every pixel
-    // in the calibrated state the gray nudge refresh expects; on X4 it is a
-    // plain HALF refresh (previous behavior).
-    renderer.displayGrayscaleBase(HalDisplay::HALF_REFRESH);
+    // OEM grayscale pipeline base: use a full sleep-screen paint so the panel
+    // enters deep sleep from a clean B/W baseline before the gray nudge refresh.
+    renderer.displayGrayscaleBase(HalDisplay::FULL_REFRESH);
   } else {
-    renderer.displayBuffer(HalDisplay::HALF_REFRESH);
+    renderer.displayBuffer(HalDisplay::FULL_REFRESH);
   }
 
   if (hasGreyscale) {
@@ -333,5 +331,5 @@ void SleepActivity::renderLastScreenSleepScreen() const {
 
 void SleepActivity::renderBlankSleepScreen() const {
   renderer.clearScreen();
-  renderer.displayBuffer(HalDisplay::HALF_REFRESH);
+  renderer.displayBuffer(HalDisplay::FULL_REFRESH);
 }