FCS errоrs hаve been discоvered оn а multi-chаssis XFM to the Top Of Rack (TOR) switch. The QSFP optics on the FlashBlade and the TOR switch have been replaced, as well as the MPO fiber cables, yet the FCS errors continue to occur. The transceiver type is still set to the default of auto. What is the next MOST plausible troubleshooting step?