it is fixed now
Thanks for the info, looks like so. Hope they fix it soon.
I think it's the impact of this incident: https://api.line-status.info/incidents/612mypbp8n7c
I was able to create Messaging API channel on Developer console, recently I was unable to do so. When selected Messaging API channel under a Provider, the next page showed only 2 fields and an unclickable "Create" button. There should be many channel profile fields to be filled but I don't see them now.
I had 3 Messaging API channels created before, I deleted one but still unable to create a new one.