Ím on a Marathon Pace Plan in Week 8 and just updated the zones in the TP settings. It all worked and the new zones are shown in the settings.
Unfortunately, those new zones are not synched with the plan im my calendar and the workouts are not updated. In the Training descriptions of each workout the Pace Values are still the ones the have been calculated at the beginning. Further, when I synch the workouts to my Apple Watch using ismoothrun, also the old zones are used. Is there any chance to really update the entire plan??
You need to ensure that you have your zones set for the specific sport and not just default in order for them to update in the future planned workouts. So if you are updating run zones, you need to create a specific run set of pace zones, apply those zone.
If you are Florian K and a TP subscriber then I have already done this for you on my side.