iOS devices automatically having VPN disabled

Good Day. We are in the process of setting up the zScaler Client Connector for MDM in a corporate device scenario. We have implemented configuration profiles for forwarding, as well as the http proxy which pushes down a PAC file. All works well once the user gets the zScaler connector app and registers their device after enrolling in MDM.

The problem we are seeing is the VPN slider within iOS settings is turning itself off at some point. It appears to consistently break overnight, after getting up in the morning a device will show all notifications come in, but the VPN services/slider is turned off. The user needs to enable the VPN slider each morning (Or open the zScaler app) to restore services. Otherwise all traffic to any app or website is completely disabled.

Does anyone know where a control or setting would be to cause iOS devices to automatically shut down VPN services?