There have been a few times when we have needed to reach out to support to help fix a few bugs. Support has always responded in a timely manner and have been very helpful in solving any problems we encounter with the app.

Great App, poor support.
For the "common variant image" set-up, here is what I find, through a really hard time.

1. Common variant image cannot be set as the variant key image. If set, there will be no common image.
2. Rule 3(Common variant image set-up) and Rule 4(Featured image set-up) is conflicting with each other. Checking Rule 4 will make common variant image disappear.

I was struggling on the "common variant image" set-up. It was really a hard time communicating with their support, who did not appear to understand my problem nor the app itself. At the end, I figured out the setting I needed by myself.