Stacks missing from Fitness+ in tvOS 17.1

Running tvOS 17.1 (21K69). Previous versions of Fitness+ allowed users to create "stacks", or group workouts in a sequence to run one after the other. With stacks, one could build a complete workout from different exercise styles and then run the workout without having to stop and search for a new workout in the middle.

Updating to tvOS 17.1 seems to have removed the 'stack' functionality.

Previously, clicking on the 'three dots' icon in the upper right of a workout displayed an option to 'add to stack'. Now this seems to be replaced with 'add to library'. Though looking closely, it looks like the 'add to library' menu item is over and obscuring the 'add to stack' menu.

Is 'stacks' gone? Or is this a bug?