Do you mean your 5G mobile data or your connection to the 48 5G network?
Do you have a connection to the 48 network - i.e. signal bars?
If not then what happens if you do a manual search for networks?
Can you see and connect to 48?
If not then what happens?
Any error messages?
If you do have signal bars then...
Are your APN settings configured correctly?
Is your phone 5G capable?
Have you checked this FAQ?
Do you have an active membership plan?
Are incoming/outgoing calls and texts working ok?
When was mobile data working ok for you last?
What changed in the meantime?
If you need to contact 48 support about this then see the links in my signature below.
