First of all I'd suggest you to uncheck the option "Automatically tune settings to keep performance level". If this doesn't solve your problem, there could also be a trainset with some wrong parameters. I'm not sure, but I believe I already read about some trainset for zigzag route having problems, that were solved uploading a new release of it. Maybe you could try to re-download the trainsets.
First of all I'd suggest you to uncheck the option "Automatically tune settings to keep performance level". If this doesn't solve your problem, there could also be a trainset with some wrong parameters. I'm not sure, but I believe I already read about some trainset for zigzag route having problems, that were solved uploading a new release of it. Maybe you could try to re-download the trainsets.