I’m surprised to see there is no answer yet, I have the exact same problem and it’s driving me nuts, I constantly miss workouts because Zwift gives the wrong information.
This is not the only topic on the subject, see Training Plan - Different "Do By" dates in Companion and Zwift APPs - #17 by Happy_Yam
Please @Zwift Team, could you put the same countdown in the app than in the companion ?
This is really frustrating and demotivating.