Why is telegram not working?

That's a real pain when it happens. First thing I always check is if Telegram itself is having an outage. You can look it up on a site like Downdetector. That'll show if it's a widespread issue.

If that's all clear, it's likely something on your end. Try toggling between your Wi-Fi and mobile data. A simple app restart can also work wonders. Finally, check your app store for any updates. An outdated app is often the culprit for these kinds of glitches. Hopefully, one of those quick fixes gets it sorted out for you.