Car not visible in tunnels in my custom road with rendered tunnel.

[Simog6]

Hi everyone. it's from a couple of patches (or maybe more) that I'm noticing this problem on my highways and I can't understand why. As soon as they pass the slope segment they disappear and then appear at the exit on the other side of the tunnel. I'm sure they worked properly before.

Is there anything to set up to make them work again?

Thanks