You’re welcome Alan.
As far as the question “If the issue is with the camera”, my answer would be that it is with the camera from the standpoint that there is no direct way to push status updates to ST from AMCrest. I would imagine that this is true for most IP cameras and would be an issue regardless of the HA hub you chose.
Again, there are creative workarounds, but it sounds like your main quest is the ability to use the camera as a motion sensor which sounds like it should be a simple thing to accomplish, but it is not really how this stuff is designed to work.
I will also add that there are other creative ways to integrate these cameras with ST. For instance, I have Blue Iris running as a service to maintain my 6 AMCrest cameras, which I have tied to my ST Modes such that the Home/Away/etc. modes can enable different profiles automatically so that the cameras will have triggers active/inactive based on the ST mode my system is currently in. Pretty cool stuff.