To clarify the problem, some more information is needed. How is your USB-installation build up. Do you use the same port for the camera and the micro? If so, is there a USB-Hub in between? Some other equipment connected by USB? Skytrak?
How long is your USB-cable in total? Be sure to use a 3.0 USB-Extension cable, eventually an active version. If it is longer than 3m it might be critical.
I use the „old“ micro connection since years with 3 cameras running at the same time without concern, using a cheap micro with an extension cable. The micro is located directly beside the Skytrak unit.
If your laptop still has this connection, I highly recommend to use it, because it might not interfere with the USB-port.
As a first step, I would try the micro on another computer, if available.
Next, have you already recorded to a voice recording program to „hear“, what sound really is delivered ?
There might be a ground noise that can prevent the differentiation between silence and action.
Does HP deliver a separate installation software for the USB-controller and do you use it?
You reported, that the micro sometimes work and sometimes not. Maybe there is an interference with your internal micro, most laptops have one. Try to set the external micro to the „default“ sound system or/and try to disable the internal micro.
If you have to set the micro value in Kinovea to 1, the sound seems to be overdriven by the system. In your system micro-settings, you may decrease the sound level.
What settings do you use inside Kinovea to record your swing. Try to use retroactive mode. Kinovea then exclusively uses the memory due to its constant recording and does not need to write the video file to the hard drive that might use a lot of CPU-power.
Open task manager to display the CPU-consumption during recording, it should not be over 60-70% of total CPU-power. I have seen other interferences if the CPU-consumption is over that value.
Try to test different settings inside the microphone USB-driver like „sleep mode“, „use mic exclusively“ or similar, if available.
If you run Skytrak at the same time, it might create a high load in 4K, as I have recognized on my computer. Try to reduce it to HD for testing or better shut it down during testing the micro.
Hope that helps somehow