If updating, uninstall any previous POS drivers first to prevent port conflicts.
Version 11.3.0.1 changes the default network timeout from 10 seconds to 30 seconds to accommodate slower networks. However, you may need to re-add the printer using the TCP/IP port wizard: Add Printer → Add a local printer → Create a new port: Standard TCP/IP Port → Enter printer’s IP → Use the new driver from the list. Pos Series Printer Driver Version 11.3.0.1 Download
Keep in mind that version 11.3.0.1 is tested to be stable on 99% of configurations – rollback should be a last resort. If updating, uninstall any previous POS drivers first