I was having similar problems with my QHY183C
I bought one of these
https://www.megabuy.com.au/startech-...e-p702601.html
But...wait there's more....got it on Amazon for $A105 delivered.
It works very well!
The full-resolution frame rate is now faster than the useless short-ass OEM cable that comes with the camera.
Full-frame RAW16 format now tops out at about 7.5 frames per second. RGB24 at 10 fps and RAW8 at 14 fps.
I am using a Toshiba WIn10 pro Tecra i7 with a 2Tb SSD ...a SSD makes a measurable improvement to the capture rates. If you have a
laptop with standard spinning-disk SATA drive, I'd suggest you replace it with a mirrored SSD. (they are quite cheap these days)
I have also used the Jaycar 5m "active" extender...very unreliable...and when it did decide to connect 3fps was typical.