Anaerobic Work Capacity - not calculated in activities

I just started to use and imported my workouts from Strava. I am wondering why the W J’ (anaerobic work capacity) data field in the several workouts is empty. Additionally or maybe accordingly, the W’bal chart becomes not displayed in the activity view even when I am selecting it from the menu.
However, in the overall power view (not activity-related) is an anticipated anaerobic capacity calculated and shown by the system.

I am asking that as a) I am interested to know how much of my capacity I used in a specific workout (I believe that is included in the W’bal chart) and furhtermore b) I would like to know if it is possible to use this value in course of defining new structured workouts with the workout builder; e.g. to avoid training overload.

Thanks for your help!

Currently you need to set W’ in /settings and then it is applied to future activities and in the workout builder. You can also edit it for any workout and then the W’bal chart will show up. Using the value from the /power page is a good start. I have an outstanding todo list item to make this automatic like eFTP.