I have a Hosted Feature Layer that I have used to create 6 View layers. I recently added 2 fields to the Hosted Feature Layer; I did so on AGO from the Data tab. After adding those fields, I knew that I would have to update the View Definition in all my View layers if I wanted to be able to see and use those fields. I was able to do so successfully on 4 out of the 6 View layers, and I am not sure why it is not working on the last 2. The fields just do not show up in the Define Fields dialog.
This has happened to me more than once, and usually I just recreate the View to "fix" it, but one of the 2 View that are not working is shared publicly, and it's a bit of a pain to get things shared publicly in my Organization, I have to go through admins. So I though I would try to troubleshoot it a little bit before I go through the process of recreating and getting it shared publicly again.