It could be that. I had a similar situation, I had a Neo CoolCam Motion Sensor that wasn’t Z-Wave Plus and a Fibaro Dimmer 2 wall switch and I couldn’t get them associated. Think it was related to S2 Security.
I had to replace the Neo CoolCam motion sensor for a Fibaro one, then I was eventually able to get them associated.
Also I’ve had issues sometimes even getting the associations to work on the Vera Plus. There is a way to do it via a LUA command instead of using Device Options in the GUI.