@Adrian.S The problem is not in the pixel or the ipad, it is in the watch that can only handle one connection for the app, at least for now, but this is pretty logical with the app and is the same for other manufacturers too (at least Coros where you can only have one active app). At least with Suunto once synced with one of the devices the info in the ipad and the pixel will be the same.
It is known that Suunto is working on improving the sensor connections to be able to have more than one, but I do not know if this will affect the app connection too.