If you also purchased the RCTimer AV Dome, it has a short USB extension cable, use that and save placing strain on the Fixhawk USB connector with repeated connect and disconnect cycles.
Using the correct technique will avoid putting too much stress on the socket solder joint and avoid damage to your Fixhawk.
Treat the Fixhawk USB connector with CARE, it is fragile, you can easily apply enough force to the USB cable plug to break the USB connector.
During initial set up of Fixhawk you will need to connect and disconnect USB many times. Do not risk breaking your Fixhawk USB connector.
Plug a USB cable into FIxhawk and disconnect and connect THE OTHER END OF THAT USB CABLE rather than directly at the Fixhawk USB connector.
Please do not interpret this to mean Fixhawk is badly made, it simply means you have to handle it carefully to avoid damaging it.
The Fixhawk printed circuit board [PCB] has surface mounted components on both sides, many of the cable sockets are soldered to one side which means there is less overalls solder holding the socket to the pads on the Fixhawk board.
When disconnecting a Fixhawk plug which side you lift up and the direction you push in both matter
To disconnect a cable from Fixhawk Do not pull on the cable
Use a small flat bladed screw driver as a lever between the flange of the plug and the top shoulder of the socket take extra care with the smaller narrow connectors such as "Buzzer" and "Switch"
Using the wrong technique to unplug a cable is almost guaranteed to damage your Fixhawk, like this broken solder joint at one end of the Buzzer socket, or worse the socket completely ripped off.
It is extremely important to handle the Fixhawk plugs and sockets correctly.
Do it the wrong way and it MAY seem as if you need something like this lever just to disconnect a cable and you risk permanent damage to your Fixhawk,