Building a new test instance I removed all of the unwanted categories before I realized I hadn’t created a welcome topic (to dismiss the banner).
Browser console shows a 403 error and the follow:
[Error] Unhandled Promise Rejection: Error: PresenceChannel '/discourse-presence/edit/10' not found
(anonymous function) (discourse-7c613daf8a1b33d792d7fc2d9330d354e7e335d1ee1a84d3521b13962937a633.js:7482:111)
asyncFunctionResume
(anonymous function)
promiseReactionJobWithoutPromise
promiseReactionJob