Following is not being driven

The obvious implementation of "follow the session" is to apply the shared state whenever it changes and correct any local divergence back toward it. That makes pause impossible: press it, the next state emission notices the divergence, and playback resumes instantly. Users read this as a broken button, not as a design.

A session is something you listen along with, not something that holds your transport hostage. The follower's local controls are its own, and the only rule is what happens on the way back in:

// adapted — names generalized; the collector maps the local running flag and dedupes it
.collect { locallyRunning ->
    val session = repository.session.value
    if (!session.inSession || session.isSource || applyingRemote) return@collect
    if (!locallyRunning) return@collect          // paused locally: leave the session running
    repository.requestSync()                     // resumed: ask where the session is NOW
}