Dictation and Siri problem over cellular data network

Thanks for the advice. Didn't realise there is a difference between resetting your device from the menu and restoring from iTunes. So, just finished the restore process, tested Siri and everything worked fine. Restored from a backup I did on my computer. And Siri still works. So I guess the problem is solved. I will test it throughout the day tomorrow and keep you posted. I am however quite optimistic and thankful for the solution.

Well, the success was short lived. It doesn't work. Last night, when I wrote the reply, I tested it for aprox. 5 minutes and it worked. This morning it doesn't work. Same problem. So the restore didn't fix it, it might have been just a coincidence, because it does work once, from 10-15 times I try. So, any other ideas? I am beginning to think that my provider is at fault. Phone works via wifi, Apple servers are responding for other apps. Might have some restrictions from Vodafone, although I can use my traffic for everything else. Could there be a restriction on Siri protocol if it is different from anything else? Or does Siri use a certain port that might be blocked by Vodafone?

So, it turns out that Vodafone has a antivirus/firewall/antimalware/anti phishing app called Vodafone Secure Net which is obviously not working properly, as it blocks Apple apps like Siri and dictation. I asked them to disable it today and Siri and dictation are back! Feels so good to be able to use my phone to its full extent.

I have asked the employees I talked to, to forward the situation to the technical department that sets up this feature, as most people, like myself, will blame it on the phone or the software.