https://community.getvera.com/t/zwave-network-on-vera-explained/210661?u=rafale77
It’s a long answer but your answer is in there. I am 100% sure. I am surprised support couldn’t help you. Maybe they should get some training. with 10 battery operated devices, and with their wakeup interval set at the default settings, you are saturating your zwave bandwidth >33% of the time. There isn’t enough time available for useful data to be transmitted. @Catman beat me to the answer this time. 