Same problem here, it does not work on my side too. All communities joined from a page does not allowed and return the following error message: You are not authorized to publish to this page. Are you sure this is even a page?. I have joined the community through my page and not through my personal profile.
I am using version 3 Pro : 3.3.1 (API Version: 2.14.8) [Pro – Multiple Accounts Edition]