I helped with my friend's Helix DSP Pro MK2 which exhibited similar results when connected to laptops. It'll prompt Connect / Connected initially and disconnects momentarily.

Tried all the things you did as well - loaded the USB drivers from Helix etc.

What ended up working for me is going into the Device Manager/Hardware Manager of the laptop and picking the USB port and manually updating the drivers from there. After that, the laptop was able to successfully connect and remain connected to the laptop for tuning.

Best of luck and hope your fix was as easy as this.