Proton VPN on an iPhone will not allow auto connect to be turned off. The only way to stop using the VPN is to uninstall Proton VPN. There are times when connected to a network that does not have internet access, there is a need to turn off the Proton VPN. I have also had problems when using the hot spot on my iPhone that I need the VPN turned off. For example when using the hot spot to allow my laptop to connect to a corporate VPN.