Fuji GX680 III refusing to shoot

I took my camera out last night to shoot downtown Austin, it went great for the first half of my roll, but once I tried to shoot the 5th shot the camera gave me an error displaying that my film back is malfunctioning. I've spent hours trying to figure it out now, checked the darkslide and battery power numerous times now and it doesn't seem to be what's causing the issue. The current frame number keeps blinking so I'm wondering if it's a problem with the back advancing my roll of film, not sure though. When I press on the "TOTAL OF SHOTS" button, the display will actually change where it says the issue lies between the lens, the body, but then it always returns to showing the problem to be within the film back. I thought to try rewinding the film to see if that might help but when I press the button while the camera is set to MULTI, nothing happens there either. The only other cause to this error that I can think of would be a connection issue between the film back and the body, but to test this I even took out the batteries of the film back to see if it would draw power from the body, and it did so I'm assuming that the connection isn't a problem either. If someone could help me pinpoint what could be causing this that would be greatly appreciated

Have you changed batteries in the camera as well? The camera is very sensitive to the correct voltage. When I tried to use the camera with 6 'normal' AA rechargeable batteries I got, more or less, the same error. Changing to non-rechargeable 1.5V AA batteries resolved my issue. Regular rechargeable AA batteries only give 1.2V. Using 6 of those will provide only 7,2V while the camera expects 9V.

I am not sure about this, but if the back is mounted on the camera and the camera is switched on, the back will get its current from the camera's power source. Hence checking the batteries of the back, assuming you are using a NIII back, does not solve the issue. Using a non-NIII back with a depleted battery still works.