Why Is The Track Surface At Spa Is So Broken?!

So for whatever reason each season I progress into the track surface gets worse and worse, I'm currently in S3 and it's genuinely causing a lot of issues for drivability, it literally bounces you off the track and there's no way to avoid it, the AI are also dealing with the bumping and it's nothing to do with ride height either because the AI run quite high ride heights on the default setups