I have recently merged accounts.
However, it looks like the chats weren't been influenced by the merge, which makes me underprivileged to participate in chat. The screenshots of the problem are as follows:
The chats homepage still shows the new account which I used after my past account was locked:
So, it looks like there was a minor glitch with the merge, where chat didn't get influenced.
[Update]: It has been two weeks and the problem persists. Looks like it isn't a caching problem.
In fact, this has been recognised and confirmed in the SFF chat too. (by @Randal'thor)