Downloading WhatsApp version 4.4.2 (or any version for Android 4.4 KitKat) from third-party repositories like no longer effective for actual messaging Current Support Status

Since you are installing an app from outside the Google Play Store, you must adjust your settings first.

Functionality: Even if you successfully install an older APK on a device running Android 4.4.2, the app may refuse to connect to WhatsApp servers or prompt you to update to a version your OS no longer supports.

Security: Using outdated versions exposes your device to security risks.

What worked (typical for that era)