Yup - that's what I've spent the last few weeks trying to get from them. I wasn't having any luck, hence my attempts to purchase it from another source.
Avin finally sent me the original harness. Looks like the new harness is meant to attach to a different style of reverse camera that does not have separate power(black or red) and video (yellow RCA) connectors; rather it has a 4pin connector seems to combine both functions.

I'm not sure if it's just COVID-related, but their support has been abysmal and extremely slow. Thanks again for everyone's help with this.