I’ve built it as well but I don’t have the issue you mentioned. Check if the components (caps/resistors) are all correct. Since you populated the PCB you probably can’t see the values anymore and there’s no schematic/doc yet.
The bottom clipping switch in the down positions should create a more open and brighter sound and in the up positions a fatter/warmer sound. The top switch goes from Rock to jazz (Bottom position). I experienced the jazz side as decreasing some high end.