I've had similar problems and one more in the web DocViewer interface, when trying to use it with a Huion 1060Plus graphics drawing tablet and active stylus connected to my Windows laptop: - the same problem with the accept/delete popup box getting in the way of writing with the pencil annotation tool; - low quality / illegibility of writing with the pencil annotation tool (which does not occur when using the same graphics tablet with other apps); - visual misalignment of the pencil annotation tool icon with the markings it makes (which appear quite a ways above the tip of the pencil icon -- though when using the mouse, they're properly aligned, I can't control the mouse well enough for writing -- again something that doesn't happen when using the graphics tablet with other apps). In my case I need pencil annotation for mathematical economics assignment grading. I've worked around this for now by using the Canvas Teacher app on an Android Samsung tablet successfully with PDF documents, but that has its own problems. (That interface can't be used to mark up JPEG files, which students were submitting work that way until I realized I had to have them combine the JPEG photos of their work into PDFs.) I've submitted a tech support ticket for the misalignment problem. Thanks.  ... View more