If you open Personal Brain and shift into: New Expanded View, then begin to edit the view to customize it (so you can save it as a custom view, e.g.), do the following:
Hover over a thought and use the minus(-) icon to remove it from the view.
Now wait about 10 seconds. For some reason, Personal Brain repopulates them into the view.
This is a very annoying bug because it takes me more than 10 seconds to lay out the Plex how I want it, and I have to constantly fight the interface for control of the view.