I am having the same problem!
I've been modding games for a couple years now, so I understand how to go about troubleshooting problems with games but yeah, this has sent me for a loop
I played around with the display, nothing. There's no way to adjust the size of the inapp windows, and i'd be fine just figuring it out but this cuts off the inputs for a couple of the buttons, which is super unfortunate.
HELP ME OBIWAN KENOBI, I'M A DUMDUM
I ran it in compatability mode with Windows 8
I'm using windows 10 on a 4k screen at 3840x1240 resolution
I thought that must be the problem and was messing around with the display settings until I remembered that this app is older than windows 10 and that it was probably the dpi scaling.
I swear I'm not a luddite lol
anyway, to reiterate, I ran it with windows 8 compatability and that seemed to work, ymmv, so basically just start pressing buttons until it starts to work.