Same here. I can add notes, but I don't seem to be able to edit any of them. I generally assign a note to a notebook at creation time, but sometimes I forget. About a month ago I went through most of my notes that weren't assigned and put them in my correct notebooks. Starting in the last week or so I have been unable to do this anymore. In some cases the save button seems to have lost it's click event handler, pressing it does nothing and I can't even attempt a save, I can only cancel. In some other cases the update service call returns a 200 ok, but the JSON has successful:false and "error saving annotation".
I don't see a feedback ribbon on the page, like most on lds.org have. I've reported it via the feedback link in the footer, but that probably just goes to lds.org, don't know that it will make it back to the notes team (if there is currently one).