Alright, @Urban_Horn, I’ve had the bug team take a look and we have been able to reproduce this issue after some trial and error.
It seems that this could be related to the series of steps you took ending in switching the custom duration caps for those workouts. We aren’t 100% sure yet, but the team is still working on it. 
Regardless the temporary workaround we’ve come up with is to switch the custom duration cap for Saturday workouts back to 90 minutes at some point before you get to the Beinn workouts. From there, if you actually want to do a 60-minute workout, use Workout Alternates to find a 60-minute replacement of your liking.
Let me know if this works for you and if you have any questions or concerns about this.
I’ll be in touch once we know more and resolve the issue. 