Argent Tournament - Can't champion new faction

I tried to create a ticket but was told to check the forums.

I have swapped factions a few years ago, which online seems to be the cause of many issues with argent tournament.
2 weeks ago I championed The Sunreavers, and then selected Orgrimmar, which I completed.
Now I am unable to select another faction to champion.
Apparently, I’ve already championed Thunder Bluff and Sen’jin, as I’m able to use their quartermaster vendors - though I don’t remember doing them - but perhaps it’s an alliance one has carried over?
The achievement however says I haven’t done thunder bluff. (It does say I’ve done Sen’jin).

Anyway, the main issue is that I now can’t select a new one - there’s no quests. I’ve tried cancelling all quests, waiting a weekly reset, etc.

Unable to choose the next faction at Argent Tournament grounds - Support / Customer Support - World of Warcraft Forums (blizzard.com)

This is sounding like a similar issue, but I am unable to post as it’s US.

It ends with the support saying they’ll look in to it - not sure if anything came of it.

-Thanks for any help and taking the time to read!

Kind Regards

Hey,
I know it’s 2 years old now, bit just wondering if you were able to find some solution to this? I’m facing the exact same issue and after contacting support the advised to look at wowhead comments, so I’m pretty much on my own!