Apple's process for fixing an iOS 14 Health App bug lost 4 months of my data!

A few days ago I noticed that my new Apple Watch 6 (on Watch OS 7) wasn't sending certain workout data (runs specifically) to my iPhone XS (recently updated to iOS 14). After some research I discovered the following article suggesting that Apple was aware of the issue and had provided a solution (albeit with no reference to whether the missing workouts would be recovered):

https://support.apple.com/en-us/HT211865

I decided I could afford to lose a couple of days run data to recover the functionality between my watch and phone so followed the process to the letter, taking care to make sure that the Health App stated that all my health data had been backed up before I reset and restored the phone. I am now several days past the phone restore and I'm missing over 4 months of health data, including some critical information about a heart condition that I had yet to share with my physician. To say that I am livid wouldn't begin to describe the disappointment.

Is there any way that this data may still be in a backup but for some reason not syncing to my phone? I read somewhere that people experiencing the issue that this bug fix was aimed at were finding multiple versions of their Apple Watch in the data source lists of their health data so I'm wondering if this is the problem. Before going through the process I had noticed that I had 4 Apple Watches listed as data sources even though I've only ever owned 2 Apple Watches. It's now only showing 2 Apple watches as data sources so I'm wondering if the 4 months of missing data were logged as belonging to one or both of the Apple Watches that are no longer listed.

Any help would be greatly appreciated.