Having trouble disabling full screen

[Jeff Smith]

I'm trying to get the game to stay open when I use my second monitor, and I read that there are two steps.

1) add -popupwindow to the game properties in the steam load options, which I did,

And 2) Enter the game and disable full screen, which is where I'm running into trouble.

when I load the game, I've had trouble getting it to show on my screen properly. When I start at my monitors resolution (720p, it's a smart TV not a regular monitor) the UI is so big that the options don't show on the screen.

So I alt-enter to get it to fit the screen properly. But that seems to disable full screen, as you can see here - https://steamuserimages-a.akamaihd.net/ugc/2502391165204611171/1DCD22B59949A1ECF21EA43B4112D69D5D9C8119/?imw=5000&imh=5000&ima=fit&impolicy=Letterbox&imcolor=%23000000&letterbox=false

I have fullscreen set to false in the prefs.xml file - <fullscreen>False</fullscreen>

Any advice?
Thanks!

[VitaKaninen]

Mine is working properly, but I did not have to mess with any fullscreen settings. I just added that line to the startup options.
Mine says Borderless fullscreen in the graphics options just like yours.