After switching from Xbox to PC, I recently went through the effort of achieving level mastery, various challenge unlocks, etc. on my Steam account before carrying over my progress from my Steam account to Epic.
The exported data from my Steam account is not current and does not include any of the things I’ve done in advance of carrying over my progress. The exported data is only up to date as of weeks ago, though it recognizes that my last login was as recent as today.
Yes, there are several people reporting this, including me. We just have to hope IOI see one of the threads and take notice.
Anyone found a fix yet or heard back from IOI? I’m still waiting for a reply to an email, really want to continue with H3 but not sure if I should bother yet if it’s all going to be erased when I carry-over 
I’m in the same boat. I’d really like a solution for this.
Hey guys, I’ve found a fix!!
You can just delete your IOI account and then create another IOI account with the same username/email address, then link your H2 and H3 accounts again, and when you go to carry-over page your H2 progress will be up to date. I don’t think there’s any downside to deleting your IOI account temporarily either, as there is no save data linked to it (at least on PC).
Edit: It may take a couple minutes for the carry-over page to find your H2 profile after you’ve linked it again, don’t worry! It will find it eventually.
Jeez, IOI really made this whole process as difficult as they possibly could.
I’ve been thinking of this too, but I was too afraid to try.
Now I took a leap of faith and can confirm, that PimpButters solution works. Thank you, thank you, thank you.
I did use a different email address though, but it worked perfectly.
As has been mentioned, you have to wait a few minutes until the carry-over website recognizes the new account.
I created my IOI account only to transfer the progess, so I don’t know, if there are any side effects.
Wait… does this work if you already transferred “successfully” but it bugged out and retained nothing?
Or is this only to get your progress updated on the summary screen? Because I did the carryover and lost EVERYTHING for some reason… I think my “summary” page was blank when I confirmed
Just an FYI: Doing this to fix a bugged transfer won’t help. As far as I can tell it’s tied to your console account… the only way I could fix this myself would be to make another psn account, buy all 3 games again, and unlock all that grueling crap again, just for another chance at a transfer…
Really wish I saw this thread when I was Googling about this. Was experiencing myself and trying to figure out how to force it to update. Finally gave up and pressed “go” against my better judgement. The result: I lost 128 xp levels, mastery and challenge progress on most of the H2 locations and many unlocks (the ones I grabbed because I knew I couldn’t get them in H3 hurt the most). If I had only found the trick above a few hours earlier… I am not pleased. 
Sorry to hear that. The carry-over process was… Not great.