Turbo Stream link not working in Show view


I have a link on a Show view with this markup:

<sl-button href="/parks/park_1/coasters/coaster_70928/soundtrack" data-turbo-stream="true" id="soundtrack_button_coaster_70928" variant="secondary" size="small" data-optional="" data-valid="">
                     <sl-icon name="music-note-beamed" label="Soundtrack" role="img" aria-label="Soundtrack" library="default"></sl-icon>

The <sl-button> does technically output a standard link. It has the data-turbo-stream attribute as required for GET requests, but when clicked, the page just does a standard page request and not a turbo-stream request and I get the following error:

# ActionController::UnknownFormat in CoastersController#soundtrack

The EXACT same code works perfectly on the Index page. It’s IDENTICAL.

I don’t need to add a format.html to the respond_to block as I ONLY need this to respiond to a turbo-stream request.

Any ideas why it works on my Index view but not the Show one?