Quite recently (in April), Telegram has been banned/blocked in Russia for refusal to give up encryption keys to Russian agencies. Telegram's defence was built around the fact that they don't even have the encryption keys for their end-to-end encrypted secret chats, naturally, and while the ordinary chats are only client-server encrypted, the encryption keys and data are stored in different places under different jurisdictions, as per Pavel Durov's blog post.
WhatsApp, however, uses E2EE by default in all chats, so even WhatsApp servers and anyone else doesn't have access to the messages... unless there's a backdoor, which we can do nothing about, or secret services just use the backups from iCloud/Google Drive (which would give them access to everyone's messages anyway).
So why the selective ban? Is it somehow related to Telegram in particular, or maybe the people behind it?