We have identified the issue. To combat abuse, we require all HTTP traffic to have either an SNI (Server Name Identification) or a Hostname header. Pyrogram connects to raw IP addresses without specifying an SNI or a Hostname header.
The issue here is that Pyrogram will need to update its codebase to support this, or users who intend to run Telegram bots on Replit will need to use a library other than Pyrogram (that is until they fix the issue) if they intend to host their Repl without using Deployments.
We have confirmed that using a Deployment does not encounter the issue as we do not require the same headers for those. If you Deploy your Repl (https://replit.com/deployments), you should be able to host your Telegram bots using Pyrogram without issues.