Can't Login to Nighthawk App? Here's the Guide to Fix
If you can’t login to Nighthawk app, there could be an issue with the app. To fix the glitches with the Nighthawk app, you can try uninstalling the app for some time.
After a few minutes, you can install the app again and the issue with the app should be gone. Also, check if your Nighthawk app requires an update. An outdated app can also cause issues. If the issue persists, you can log in via the web browser.

https://nighthawklog.net/night....hawk-app-not-working