You might need to refresh your connection.
To do this, go to the 'Calendar tab', select your last period, change the dates and tap 'Done'. Next, revert the period back to its original dates and tap 'Done' again, then close the app.
Once you’ve done this, try opening the app on your partner’s device to see if they've received the latest cycle changes.
If this still doesn't work, feel free to reach out to us for more assistance.