A big reason for this could be how your EV handles internet connectivity. Even when your phone is connected via Bluetooth or a cable, Siri still needs a solid data connection to process requests. Some cars, especially EVs with built-in Wi-Fi or hotspot capabilities, can mess with how your iPhone prioritizes data. If your car’s system is trying to take over the connection (but doesn’t have an active plan or good signal), Siri might be getting stuck in limbo.
A quick test: Try turning off Wi-Fi on your iPhone while you're in the car and see if Siri works better just using cellular. If that helps, then your car’s Wi-Fi is likely interfering.
Also, if you’re using CarPlay (wired or wireless), check if your EV has any firmware updates available. Sometimes automakers push updates that improve connectivity issues like this.
Another possible issue—network strength. If you're driving in an area with weak cell coverage, Siri might struggle more, since it’s relying on your phone’s connection to process commands. Lastly, some people have had luck resetting their network settings on the iPhone (Settings > General > Transfer or Reset iPhone > Reset > Reset Network Settings). Just keep in mind this will erase all your saved Wi-Fi passwords.
Hope one of these helps