I followed all the instructions as set out in the troubleshoot guide at: https://community.48.ie/t5/The-Knowledgebase/The-Roaming-Troubleshooting-Guide/ta-p/52179
But the problem persists - when I try to save down the 48 details they just don't show up. Also if I delete all existing APN's and enter 48 details a message shows up that "Access Point Name settings are not available for the user". When resetting the default four different APN appear all by the name of "Proximus". I also tried to change the setting of one of those and amend it with the 48 details, but again no luck.
For your information I am currently in Germany and I am desparate to get this sorted. Just to say that regular phone is working fine.
Eventually I got some help - after being on the chat with 48 staff for over an hour and playing through the options, I eventually was sent a configuration SMS to reset the phone/SIM. That then enabled connetion to data, but only very poorly. I then changed for LTE/4G Setting to 3G and it works a dream ever since. I'm assuming that this is problem with the "Three" network 48 is using, as I had similar problems before when being on Three contract. Just to note that I encountered my problems in Germany, Holland and Belgium.
Thanks for all replies.