Signal and Telegram users have been reporting problems accessing the services. It’s unclear whether the outages are connected to each other, or what the reason for the services being offline might be. Both services are now beginning to come back online, although some users are still reporting problems connecting. Telegram posted on Twitter, apologising to users affected in Europe, the Middle East and North Africa. Until either service shares details, its just speculation whether the services have been successfully targeted with a distributed denial-of-service attack.”]
Source: https://grahamcluley.com/signal-telegram-messaging-services-offline-hours/