VOIP with HT503

Hello, I have a Ignition voice alarm configuration setup with the HT503. Everything is working aside from the fact that the system does not seem to be calling the contacts on the Callout Roster list. The system calls the first number on the list and does not continue to make calls until the alarm condition has been acknowledged. The alarm pipeline is setup that it will only drop out of the pipeline once acknowledged. When i monitor the alarm pipeline status it does show that it is calling “user 1”, then “user 2” then “user 3”. All of this in the time span that it actually calls “user 1”.

I believe it maybe a setting in the Grandsteam HT503 and/or some sort of time delay setting? Anyone have any suggestions?