• Your Rocket.Chat Experimental app version: 4.10.0 (develop)
• Your Rocket.Chat server version: 3.2.2
• Device (or Simulator) you're running with: Simulator - iOS 13.6 on iPhone 11 Pro

When you Pin a message, it's "pinned" state isn't immediately updated internally.
Immediately reopening the Action Sheet for the message shows the option to Pin again.
Leaving it a second before opening the Action Sheet (or closing and reopening) shows Unpin as an option, but the unpinning suffers the same problem - if you immediately try to pin again, you'll only be offered Unpin.

This issue also exists for Star/Unstar.

Apologies for oddly low speed GIF. That's some odd mov-to-gif conversion to satisfy the GitHub gods.