I can access internet via cellular network with no issues. However, when I connect to another device using WiFi that is not connected to internet (eg. OBD2 scanner) my access to internet via cellular network no longer works! Why?
iPhone 11 Pro
Why?
iPhones prioritize a Wi-Fi connection over a cellular connection, no matter whether the Wi-Fi connection has an Internet connection or not.
If the Wi-Fi connection to which the phone is connected does not have Internet access, then your phone will not have Internet access.
I don't understand though, why you are not connecting the scanner to your normal Wi-Fi network. Then, your phone will be able to connect to the scanner and the Internet at the same time, and you won't have to change networks to use the scanner.
Why?
iPhones prioritize a Wi-Fi connection over a cellular connection, no matter whether the Wi-Fi connection has an Internet connection or not.
If the Wi-Fi connection to which the phone is connected does not have Internet access, then your phone will not have Internet access.
I don't understand though, why you are not connecting the scanner to your normal Wi-Fi network. Then, your phone will be able to connect to the scanner and the Internet at the same time, and you won't have to change networks to use the scanner.
Re scanner connecting scanner to home WiFi, the car scanner can’t get close enough to get a signal to WiFi hence need iPhone WiFi…
In any case, from what your saying, there is no real technical reason why both cellular and WiFi networks can be active at the same time, it’s just iPhone prioritizes WiFi and blocks cellular data…
This is a serious limitation due to a basic design flaw in iPhone/iOS!
Why couldn’t iOS developers add a setting to force internet access using cellular data regardless of any WiFi connection???
"Why" questions about product design and feature choices can only be answered by Apple....and they are not here on this user-to-user site.
If you want to make a suggestion directly to Apple, you can do so using this link:
Feedback - iPhoneAppleApple › feedback › iphone
If you added a Wi-Fi extender in the area close to your car, then your phone and the car scanner could connect to the same home Wi-Fi network, and you would not have to "switch" networks at all.
Accessing internet via cellular network while connected to Another WiFi device
