When I move away from a Wi-Fi zone, my phone does not automatically connects to mobile network even if there is full strength of mobile signal. It connects to mobile network only after I restart the phone. How to resolve this problem?
iPhone 14 Pro Max
Hello SMITH_SL,
Let's try the steps below and check the cellular settings on your phone to ensure they are set up to how you want them to be for your cellular service and what can access the cellular data.
"Set cellular data use for apps and services
Go to Settings 
> Cellular, then turn Cellular Data on or off for any app (such as Maps) or service (such as Wi-Fi Assist) that can use cellular data.
If a setting is off, iPhone uses only Wi-Fi for that service.
Note: Wi-Fi Assist is on by default. If Wi-Fi connectivity is poor, Wi-Fi Assist automatically switches to cellular data to boost the signal. Because you stay connected to the internet over cellular when you have a poor Wi-Fi connection, you might use more cellular data, which may incur additional charges depending on your data plan. See the Apple Support article About Wi-Fi Assist."
More cellular settings can be found in this article: View or change cellular data settings on iPhone
Let us know if you have any questions.
Thank you for using Apple Support Communities.
Take care!
Issue in shifting the connection from Wi-Fi to mobile network
