Combining Fitness App Data from Multiple Devices

I started using my old Apple Watch again. It's paired with my phone. Fitness tracking is enabled on both devices (watch and phone).

However on my phone it only counts activity from the watch (but in hourly graph for today it shows the steps from today before the watch was paired).

On the watch the the fitness app is counting only the steps from before the watch was paired.

How do I combined the data from both devices in the summary screen(s) of my fitness app?