I am also seeing this issue. This is a hard one to search for. Pajh, did you ever figure out a solution?
The standalone binary is useless because of this. The steam build works better surprisingly. The main difference between the two seems to be that the steam build registers UI events more consistently, particularly mouse-over events. Ex. clicking a box usually does nothing in the standalone version, but moving my mouse will make it work in the steam build. Typing a string in a text box will always type the last character I pressed, as described above. In the standalone build, clicking the confirmation box doesn't do anything and the last char in the string is still missing. In the steam build, hovering over the confirmation box will make the last character appear, and the button usually works.
I am also on a Dell. The XPS 15 2-in-1 specifically, is this what you have pajh? I'd be glad to help debug it if someone can get me set up with a debug env and/or show me what sections of code I should instrument.
Thanks