The app’s developer set android:exported="false" on all activities. Root your device and use the “Show non-exported” toggle in QuickShortcutMaker settings.
Version 2.4.0 is a polished bugfix release rather than a feature overhaul. If you are using 2.3.x, upgrading is recommended for stability on Android 9–11. QuickShortcutMaker 2.4.0 APK Report for Android
This is where many legacy APKs fail. QuickShortcutMaker 2.4.0 was last updated before scoped storage and background activity limits. Here is the current compatibility matrix based on crowdsourced testing (XDA Developers, Reddit r/Android, Telegram groups): QuickShortcutMaker 2.4.0 APK Report for Android