Bug: Boost button appears live on unboostable posts

[a-dows]

In the Mastodon web interface, the Boost icon on a followers-only post is grayed-out to indicate the post cannot be boosted:

But the same post in Ice Cubes shows a live Boost button that flickers when interacted with:

This gives the impression that there's an error or a failure to Boost. Instead, the followers-only posts should have a visibly distinct boost button that is not interactive.