When was it working ok for you last?
Where are you located?
Do you know anyone else in your area on 48 to see what their experience is?
Are your APN settings configured correctly?
Is your phone capable of using 5G?
Do you mean that you're getting 4G connectivity and speeds?
What sort of download and upload speeds using a speed test site/app?
Maybe you could try a replacement SIM in case that helps?
If you need to contact 48 support about this then see the links in my signature below.
