How to pin more than 5 chats in Telegram?
On Telegram mobile clients, when activating a proxy with a sponsored channel, you can pin 5+ channels. This is shown on the screenshot.
If you turn off the proxy after that, the pinned chats will remain in place. But when you try to add another one, a message will appear with a limit of 5 chats.
So if you enable the sponsored proxy, pin 10 chats, and disable the proxy, then all 10 chats will remain pinned.