Ok I used the lsusb command on terminal and attached is the result.
As suggested, the first command is just with the usb to serial adapter. The second is with the mount connected to the adapter (see the attached image). Kubuntu is indeed seeing the usb to serial adapter. And it's also seeing the mount.
If I create a profile with just the CEM60 mount and simulators for the CCD camera, guider and focuser, Kstars is capable of seeing the mount. It also works when I add the Canon DSLR, Orion SSAG and Microtouch focuser, Kstars.
Go to "Connections" tab, and try to select another port (maybe /dev/ttyUSB1) and then try connecting again. If you're using StellarMate, use the StellarMate Serial Port Mapper to permanently assign ports to both the focuser and mount (e.g. /dev/focuser and /dev/mount) so that they don't both try to connect to the same port.