iwatch and apple health - same health details on 2 different watches

I have an existing apple watch and recently bought my wife one - the problem we are having is that the health details via the health app are the same on both iwatches and both iphones, even though they are connected to different watches. If i change the details in the profile on one one phone, it then changes it on the other phone.

My wifes phone also is recording sleep from my iwatch and not hers - and hers doesnt even appear in the data sources so i cant select her iwatch as the data source.

All other data sources are the right way around on both iwacthes/ health app, although at first both apps were taking the data from just my iwatch.

we are all on one icloud account