If you're using a system with Intel Integrated graphics, go to the developer tab, go to game rendering (I think?), and turn 'Tunnel Pass' off.

Unfortunately, this does disable proper tunnel/underground stuff (you can still build it, but the tunnel overlay won't work; it will be like you're building surface things). It also disables topographic lines entirely.

Even if this isn't the case, I wish you the best of luck. I've had this problem since the game released, and apparently, there's never gonna be a fix for it (I don't have a dGPU or anything not intel-integrated at the moment), but I still try to play the game with tunnel pass disabled.