Just started the game and came to report the same issue. It seems it's known one as there are several posts already. Someone also mentioned Lead Soles and 170mph in Heavy Traffic too, but I did Lead Soles and it worked fine. So far it's only Halawai. When the race finishes the finish screen appears but the game doesn't seem to register the end race. Steering and the gas are locked but I can shift gears, start/stop the car and look around. Mouse clicking moves the camera. But there's no way to click "Next" and the confirm button (Enter) doesn't work. Only way out is exiting the game. The win and the money are counted so not a huge deal though.
Now that you mention it, I think I saw a way to edit the default races. Might be worth a try moving the finish line around if possible, and see if the issue persists.
EDIT: Well, I figured it out *for the most part*
First I modified the finish line, closer or farther away, it didn't matter. Went back to the original track from the unmodded game (RSFE0024.IGE), the original Halawai is a very short race with 4 checkpoints, 3 bots and $5000 prize. The original worked fine, so I started from there. I recreated the Platinum track but by doing that I also replicated the bad finish. I went back, only modifying the race course, keeping the 3 bots and prize. That worked, I raised the bots to 5 and the $10000 prize. Also worked. Upped the bots to 7, ALSO worked.
Wtf was going on? I deleted RSFE0024.IGE, started over again. Checkpoints and 7 bots. Bad finish. Started again, checkpoints and 5 bots. Worked. Went to 7 bots. Worked. Restarted the game, bad.
In the end it's the bots number the issue. Apparently the first time you do the race from a "fresh boot" of the game, the bot number has to be no more than 5. With the race once completed you can go to the editor and raise the bots to 7 and it works. But if you restart the game and try again the 7 bots give you the bad finish. If we want a race that universally works it's better to stick to 5 bots. What a very odd issue.
Attached is my version of the Halawai Boulevard edited from the original (unmodded) file. Same layout as Platinum version but with less checkpoints (8, Platinum has more but some are redundant), 5 bots and $10000 prize, other settings untouched. Tried it several times from a fresh boot and it always gave me the proper finish screen.
RSFE0024.IGE