I'm guessing you've messed around with it so much all the settings are out of kilter now, best bet is to go to an iStore and get them to reset it and talk you through how to use it properly.
Do you have roaming switched on (on the phone) and active (with your provider)? Sounds like your data issues are only a problem when away from wifi.
I did a reset to get pictures to show properly. If there is some secret setting that prevents pictures being uploaded without Wi-fi, then I am screwed. Doesn't matter now as it's not a given that it will make it home. But I need the number, so yes it will. Definitely, it will never ever leave the UK again. It's not even a given that it will ever leave my house,
I agree you certainly can "Jail Break" an iphone. But people don't seem to feel the need anymore. Looking back six plus years there were regular mentions on social media, top tips on doing it, and frequent discussion making it a common topic. Not anymore. I think the products have changed, and many peoples attitudes too. My Google apps run really well on my Apple hardware, & seamlessly alongside iOS/ iPadOS and presumably macOS. But you're right, à chacun son goût!
I jailbroke an Android phone years ago. I cannot remember why. The only thing that I can think of, is setting the phone free from being tied to a particular network provider. I think that phones are released after two years anyway. On my iPhone, or Android ones, there's nothing to bother me, so no reason to break out of jail.
Perry I was in Santander last year and my iphone was perfectly fine, as was my Apple carplay & ipad. They were all fine throughout four countries, for an eight week period. So yours should be as well! Perhaps you are in an area of crap Wifi? Could you have accidentally adjusted a setting? This is a vid to rest your network settings, without resetting your iphone. Perhaps it may help?
I did that. I had to reconnect to the hotel WiFi so it certainly did something, but I don't know if it has helped. The only thing that I noticed is that data roaming is now OFF. It's connected to Orange now (that was the weakest signal) but I give no shits, it's sorted. I won't know until I venture out.
Outside of hotel WiFi nothing changed, although I could call my other phone in England. I get no data, whatever network I choose. Doesn't make any difference whatever the setting. So after this farce, the phone never leaves the country. If data doesn't work without WiFi in England, that is it. I'll go back to a physical SIM. Although I can use the physical SIM with an eSIM on my Android phone, I will have options. The result of which, there will be no ESIM for the iPhone, rendering it useless. No loss there.
If you have data roaming switched off you won’t have internet unless you are connected to 4g / 5g on your network provider. With data roaming on it will use another provider to give you internet. (You could get charged extra for that)
