[MM-62961] Fixed pointer event of submenus (#30219)

webapp/channels/src/components/menu/menu.scss

@@ -12,6 +12,7 @@
         box-shadow: var(--elevation-4), 0 0 0 1px rgba(var(--center-channel-color-rgb), 0.12) inset;
     }
     &.AsSubMenu {
+        pointer-events: none;
         & .MuiPaper-root {
             box-shadow: var(--elevation-5), 0 0 0 1px rgba(var(--center-channel-color-rgb), 0.12) inset;
         }

webapp/channels/src/components/menu/sub_menu.tsx

@@ -189,6 +189,7 @@ export function SubMenu(props: Props) {
                         autoFocusItem={isSubMenuOpen}
                         sx={{
                             py: 0,
+                            pointerEvents: 'auto',
                         }}
                     >
                         {children}