What country are you in?
Only EU/UK are covered by roaming data allowances.
In some other countries you can use mobile data but have to pay for it from the cash credit balance on your account:
For roaming issues the usual general advice applies...
If your SIM predates January 2023 then a replacement may mitigate or eliminate roaming problems:
It may be worthwhile reviewing these two threads in case any of the suggestions help to avoid roaming problems:
If you still have problems then you'll probably need to contact 48 support for further assistance.
See the links in my signature below.
