Hi. Hopefully you have figured it out by now but I just had a similar problem and I was able to fix it. I downgraded last night from iOS 16.2 to iOS 16.1.1. Everything was good except for health and fitness. Luckily I was able to fix it. What I did was turn off “Sync This iPhone” under Health iCloud settings. Then I proceeded to click “delete from device”. The old health data is still in the cloud. Now go into the health app and you will see everything start to repopulate. After that you can go into the settings app and re-enable the health setting for “Sync This iPhone”. This worked for me so I hope it does for you too!