From an online review,
Accordingly, it should at least be compatible with the 3B, and I assume our Companion software should work with it since it works with the other Raspberry Pi cameras. My guesses then are that either your existing RPi 3B has a hardware issue related to the camera, or there was some unanticipated change when you were trying to enable the camera (which I suspect is unlikely, but if that’s the case you could fix it by flashing on a fresh Companion image).
BlueOS (our new replacement for Companion) should work on the RPi 3B+ (and 4B), but unfortunately does not yet support the Raspberry Pi cameras (although that is something we’re working on).
Apologies I wasn’t able to respond sooner, if that would have influenced your decision. Our camera should work well, but if you bought it on the grounds that another camera we support wasn’t working as expected, and then manage to get that camera working, it should be fine for you to cancel that order and/or return the purchased one if you’d like to 
Assuming you choose to stick with our camera, I hope you enjoy using it