On the ZWO webpage for the 294MC there are some reference dark frames that you could consider comparisons with. The link to the dark frames (3 TIFF files) is about half way down the page in the
Dark Current section ......
https://astronomy-imaging-camera.com...94mc-pro-color
I had a look at them and they are very different to yours. Their image titles suggest that they are taken at 100s and 300s at UG (Unity Gain) with one in HDR, whereas yours are at gain 120.
As a starting point, why don't you try to see if you can get the same results at Unity Gain with your camera and then probe further. Unless of course someone here has some higher gain darks you could compare your darks to.
Best
JA