I've been running FT8 on my 6300 for 6 months and it was working well until recently when I added a second monitor to my computer and moved a few things around on the desk. I did not change any other connections on the computer or radio. I also recently upgraded to the latest version (v1.9.1 r8747). Now I find that FT8 randomly stops when WSJT commands the radio transmit. For instance I can call CQ on FT8 and it works fine for a random number of RX/TX cycles then won't transmit when it should. FT8 is not timing out... it has happened after just a couple of RX/TX CQ cycles, or it can happen after 8 cycles, or it may not stop at all. When it happens I don't hear the relay in the radio switchover to TX while WSJT thinks the radio IS transmitting. I looked at the CAT settings and nothing changed. To resolve it I have to shut down WSJT by going into the Windows 7 task manager to kill the instance of WSJT, then restart it and repeat the cycle. If I just shut down WSJT normally (hit X at the top right) it still stays resident (Task still running) and if I try to restart it then I get the dialog message stating that another instance is running. I have to go into Task manager and end the process. The computer is a Lenovo Thinkcentre i5 running Windows 7 Professional. Any thoughts or suggestions ?