Hi
It may help to check your settings:
- On your iPhone, in the Watch app, go to: My Watch (tab) > General > Wake Screen.
- Under the heading "On Screen Wake Show Last App", select your preferred behaviour.
- To have the watch face return to the time rather than the last app used upon raising your wrist, select "While In Session".
- Note that session-based apps that are still in session (such as during a workout) will still be shown upon raising your wrist.