New version was found on 7.13.0.0 under settings about and check for express updates. no info in release notes yet.
I did the update and copied my activities back into the Activities folder on my Fenix 6X. I then synced again and the files stayed in 6X. No problem identified.
I copy all my activity fit files onto my computer so it was straight forward for me.
It did take about 10 minutes to upload all the fit files once I removed my 6X from the cable but it works ok.