Congratulations on finding a new permissions problem
You can’t edit the wiki because your Discourse groups aren’t updating. That’s a fairly common problem, and it’s basically always due to failure to match somebody’s Discourse and Neon accounts.
Your accounts, however, are fine. Your email addresses match and Neon knows your Discourse handle. I cannot explain your missing group membership.
I’ll keep digging into it, but in the meantime I’ve manually fixed your Discourse group. If you log out of the wiki and log back in you should be able to edit.