Thought so. Let me guess: You don't have the Field Marshall edition, but purchased the expansion pass separately?
If so then there's your problem. It's "WAD" that you don't have it in the sense that everything is working completely correctly. It's a design flaw and it was to be expected that the people who lke you purchased the expansion pass, but didn't have the FM edition wouldn't get the expansion registered. What's happening is that the API which is used for the synching only looks for product keys for the expansion itsel (or something like that), and since you have an expansion pass key you don't have an TfV key and hence you won't get credited with the expansion as the API acn't see you have it.
Those of us with the FM edition then got it due to the expansion icon and accompanying avatars being merged into the FM icons (meaning that now is four pictures large...).
Obviously if you got the expansion pass separately and not from the FM edition no "fix" will have been made for you. Hence it's "WAD" that you don't have it.
That it's unintentional is something else, but you not having it is a completely logical consequence of how the system is set up and could have been expected. (Though obviously nobody thought about this possibility until now.)
@TinyWiking you'll probably want to look at this.
Also those of us with the FM edition still don't have the TfV avatars (I don't at least), so the fix you tried obviously didn't work.