Problem mobile data after leave or turn off wlan

ricok

Hello together, maybe somebody can help.
Now I have a massive problem with trasfer or switch to mobile data. Some time before it was occasional now actually constantly.
If I leave a connectet wlan, an also if I switch of wlan on my phone by hand, it is impossible to transfer mobile data. But! I see the double symbol on the status bar (big and smal 3G or 4G) for active mobile data. Also comes al VOLTE-symbol. But browser or ohter applications means, there is no internet connection.

Here only helps to switch into flight mode or restart the phone.
I read somewhere, there is a bug in anroid after 3 hours, but this also happens after only a few seconds.

So I try with reset the phone and also install all firmware versions from here (with SPFlsh-Tool) from 20170112 to 20170605, also format whole flash. Nothing helps.

Somabody any ideas?

Thanks ricok

piwaii

Hi
Have you checked your APN ?

ricok

Thank you first.
First of All i checked.  Sometimes, especially after activating and deactivating the flight mode mobile data works.
I think, if APN isn't the problem.

piwaii

When in developpers mode, just before the USB config. there is an option "mobile data always ON" to make it faster swapping between wifi and mobile data network. Tried this one ?

ricok

\n\nOK, now I tried this, also unsuccessfull.
I think anyway, it isn't the connection to the mobile data network. It seems to be a good connection, because it's shown the VOLTE-symbol and it's possible to take a call over LTE, even in HD.