Your browser does not seem to support JavaScript. As a result, your viewing experience will be diminished, and you may not be able to execute some actions.
Please download a browser that supports JavaScript, or enable it if it's disabled (i.e. NoScript).
I create a new document in pixel. I set the size of my artboards and save as a preset but it does not appear in the list afterwards.
Windows 10.
@PatrickM This can be replicated easily. it is a bug, added it to the backlog.