Context:
1000+ Hour xbox account was linked (not merged) to my couple hundred hour PC through the connections page before merge was available.
Upon first login onto an xbox on day one merge was available, I loaded straight into the main menu (as my account was already linked) but had no merge option in the menu and the account now had the PC progress - level 600 overwriten to 100, skins, gold guns earnt previously on the xbox account gone e.t.c.
Relogging on PC and xbox did not fix the issue
I then unlinked the accounts and then loaded overwatch again on xbox. I was then prompted to link it to an account with the QR code pop up, which i followed, linked the xbox account to PC blizzard account and was once again greeted to the main menu with no option or prompt to merge with the xbox account being overwritten by the PC account progress.
Over a year since release I tried again (one year cooldown on account linkings) and the issue still persists
Multiple support tickets have been opened and closed with support only linking generel merge help forums.
After reading through the forums it looks like other xbox users have and still are experiencing the same issue and they all also had their accounts linked before merge was available.