This kind of thing happens all the time to me. It is now working. Not sure what I did, but I must have done something right.

OK, now it is not working. i did not change anything from when it worked the one time. I'll have to try to figure out what it could be.

This is a very obstinate bug. Most likely it's caused by a mod conflict, but every time I think I've found the culprit, it turns out I'm wrong. At first I thought it was Advanced Vehicle Options as the Road Customizer worked perfectly fine after disabling it, and afterwards the same thing with Enhanced Road Heights. The only thing I've managed to conclude is that it's entirely arbitrary what other mod seemingly ends up botching the customizer.

Which other mods do you have active? I'll see if I can replicate the bug.

I have the same problem too

me too

Same here for me. Lane changing still works, apparently; and it even seems that the custom speed limits I set before the mod broke are still working. But I cannot set new ones.