I have a client with an MFC-9140CDN printer, connected via the network. Recently upgraded to win 11 on the PC. Latest firmware installed on printer and latest software, drivers and utilities installed on PC. (and reinstalled twice!) The printer reports it is duplex, but control center 4 does not show the duplex options. I have been through all printer properties and enabled two sided on everything that showed that option. I never got the option to install duplex in the device manager properties dialogue box. Any help appreciated.