diff --git a/Marlin/src/pins/stm32f4/pins_FYSETC_S6.h b/Marlin/src/pins/stm32f4/pins_FYSETC_S6.h
index decf4aeb6bca..7616d744cba8 100644
--- a/Marlin/src/pins/stm32f4/pins_FYSETC_S6.h
+++ b/Marlin/src/pins/stm32f4/pins_FYSETC_S6.h
@@ -273,7 +273,7 @@
       #define BOARD_ST7920_DELAY_2  DELAY_NS(48)
     #endif
     #ifndef BOARD_ST7920_DELAY_3
-      #define BOARD_ST7920_DELAY_3 DELAY_NS(600)
+      #define BOARD_ST7920_DELAY_3 DELAY_NS(640)
     #endif
   #endif
 
diff --git a/Marlin/src/pins/stm32f4/pins_RUMBA32_common.h b/Marlin/src/pins/stm32f4/pins_RUMBA32_common.h
index 24c32d6d818c..959e893edc06 100644
--- a/Marlin/src/pins/stm32f4/pins_RUMBA32_common.h
+++ b/Marlin/src/pins/stm32f4/pins_RUMBA32_common.h
@@ -180,7 +180,7 @@
       #define BOARD_ST7920_DELAY_2 DELAY_NS(48)
     #endif
     #ifndef BOARD_ST7920_DELAY_3
-      #define BOARD_ST7920_DELAY_3 DELAY_NS(600)
+      #define BOARD_ST7920_DELAY_3 DELAY_NS(640)
     #endif
   #endif