By CAT default this radio uses RTS at ON, this looks like a conflict command between software.
I decided to use DTR for every program. For me this was easier without any conflict with DxCommand, WSJT, N1MM, MTTY,,,, (PTT, CW, FSK_Ext64).
You cannot mix-up Yaesu port driver, information to be found in CAT installation manual.
To always install a new driver port without any USB connection, then to connect Codec USB cable with the radio at power Off, you should see the new COM Port from device manager with the new assigned port number.
Now we can turn On the radio. The computer will keep these 2x new Codec USB port numbers.
There is no problem to delete them and to reinstall the driver.
73, Rejean, va2am