diff --git a/css/leptonChrome.css b/css/leptonChrome.css
index b994874..366f8b8 100644
--- a/css/leptonChrome.css
+++ b/css/leptonChrome.css
@@ -10621,6 +10621,9 @@
         }
       }
     }
+    #mainPopupSet:not(:hover) ~ #navigator-toolbox:not(:hover, :focus-within) #nav-bar:not([customizing]) {
+      -moz-window-dragging: no-drag;
+    }
     @media (prefers-reduced-motion: no-preference) {
       #nav-bar:not([customizing]) {
         transition: margin-bottom var(--uc-autohide-toolbar-speed) var(--animation-easing-function)
@@ -25716,6 +25719,14 @@
     opacity: 1;
   }
 }
+@media (-moz-bool-pref: "userChrome.autohide.tabbar") and (-moz-bool-pref: "userChrome.autohide.navbar"),
+  (-moz-bool-pref: "userChrome.autohide.tabbar") and (-moz-bool-pref: "userChrome.tabbar.one_liner"),
+  (-moz-bool-pref: "userChrome.autohide.navbar") and (-moz-bool-pref: "userChrome.autohide.navbar"),
+  (-moz-bool-pref: "userChrome.autohide.navbar") and (-moz-bool-pref: "userChrome.tabbar.one_liner") {
+  #mainPopupSet:not(:hover) ~ #navigator-toolbox:not(:hover, :focus-within) #nav-bar:not([customizing]) {
+    -moz-window-dragging: no-drag;
+  }
+}
 @media (-moz-bool-pref: "userChrome.autohide.tabbar") and (-moz-bool-pref: "userChrome.autohide.navbar") and (prefers-reduced-motion: no-preference),
   (-moz-bool-pref: "userChrome.autohide.tabbar") and (-moz-bool-pref: "userChrome.tabbar.one_liner") and (prefers-reduced-motion: no-preference),
   (-moz-bool-pref: "userChrome.autohide.navbar") and (-moz-bool-pref: "userChrome.autohide.navbar") and (prefers-reduced-motion: no-preference),
diff --git a/css/leptonChromeESR.css b/css/leptonChromeESR.css
index fa621c3..96a7a64 100644
--- a/css/leptonChromeESR.css
+++ b/css/leptonChromeESR.css
@@ -11059,6 +11059,9 @@
         }
       }
     }
+    #mainPopupSet:not(:hover) ~ #navigator-toolbox:not(:hover, :focus-within) #nav-bar:not([customizing]) {
+      -moz-window-dragging: no-drag;
+    }
     @media (prefers-reduced-motion: no-preference) {
       #nav-bar:not([customizing]) {
         transition: margin-bottom var(--uc-autohide-toolbar-speed) var(--animation-easing-function)
diff --git a/src/autohide/_navbar.scss b/src/autohide/_navbar.scss
index 290de4b..15d8eb7 100644
--- a/src/autohide/_navbar.scss
+++ b/src/autohide/_navbar.scss
@@ -17,6 +17,11 @@
   }
 }
 
+// Drag & Drop Event #820
+#mainPopupSet:not(:hover)~#navigator-toolbox:not(:hover, :focus-within) #nav-bar:not([customizing]) {
+  -moz-window-dragging: no-drag;
+}
+
 @include Animate {
   #nav-bar:not([customizing]) {
     transition: margin-bottom var(--uc-autohide-toolbar-speed) var(--animation-easing-function) var(--uc-autohide-toolbar-delay),