Hello,
I logged in recently on snapcraft.io using my Ubuntu one account, this pulled in the username.
I updated my username after that, on Ubuntu one, it’s fine there but this did not reflect on snapcraft io as you can see on https://snapcraft.io/publisher/login-ubuntu-com-clever596 which is my random username.
I tried to update my full name, it worked fine but the username never got updated. I’ve been told on Matrix chat that making a request here would help 
Thanks!
I don’t think roadmr is still on the @store team so I’ll ping them for you instead (with this post)
Here is an example of it messing up previously for myself, and my request that it be fixed for future users like yourself. It seems that the fixing has not been done and I’m sorry that you got stung by it. We really need the store team to get this locked-in properly to allow all name changes in the future to not cause such headaches.
Edit to add the link to the example I mentioned in the previous paragraph, which I forgor
Heads' up on another impending name change in the store