unable to create new topic in the SEA subcategory
I believe it’s because you’re not part of the “Region-SEA” group.
To join it, click on the three horizontal bars (referred to as “the hamburger icon” by some) here:
Then, click on “groups” here:
Then, just scroll down the groups list to find the “Region-SEA” and click “join group” here in order to post in the SEA Guilds, Teams, etc. category: