From 59a699063a49c1384c184c22ddccc12aa9feb538 Mon Sep 17 00:00:00 2001
From: Scott Lahteine <github@thinkyhead.com>
Date: Fri, 24 Nov 2017 15:47:29 -0600
Subject: [PATCH] Fix #8537

---
 Marlin/ultralcd.cpp | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/Marlin/ultralcd.cpp b/Marlin/ultralcd.cpp
index 9578a593c..1e4f961cd 100644
--- a/Marlin/ultralcd.cpp
+++ b/Marlin/ultralcd.cpp
@@ -4607,10 +4607,11 @@ void lcd_update() {
 
     lcd_buttons_update();
 
-    #if ENABLED(AUTO_BED_LEVELING_UBL) || ENABLED(G26_MESH_VALIDATION)
-      const bool UBL_CONDITION = lcd_external_control;
+    #if ENABLED(AUTO_BED_LEVELING_UBL)
+      // Don't run the debouncer if UBL owns the display
+      #define UBL_CONDITION !lcd_external_control
     #else
-      constexpr bool UBL_CONDITION = true;
+      #define UBL_CONDITION true
     #endif
 
     // If the action button is pressed...