So I reinstalled my laptop the other day, and restored my copy of LFS. Went into the game and noticed that I could'n enter Single player or Hot lapping. I downloaded a fresh copy of the game, installed the game and tried again; same problem.
The thing is, there is a clash with some kind of Win10 gaming interface (dont know how to call it) that leaves a rectangular area at the right side of the screen (where the interface window is "hidden") where LFS cannot recognise the cursor after the launch (that problem occurs anywhere, not just in main menu). It goes away as you minimize and open LFS again. But it should not happen in first place anyway.
Often people tell "it doesn't work" but they don't explain what happens on the screen, maybe there is some message or something. I didn't know what is your case, thats why I asked for screenshot Nice you found a solution!
Disabling Windows 10 game bar by going to Settings > Gaming > Game bar and turning off "Record game clips, screenshots and broadcast using Game bar" should resolve the issue and eliminate the need of minimizing and maximizing the game.