sometimes my internet is fiully blocked. Whlle displalying 4,G

A t these times, sometimes I inactivate my GPRS and then activate it. Some times I reset setting in my mobile phone samsung s8. It answers on and off.
Last 2 notions
,1) its been the 5th month samsung all day is engaged in my back-up restoring.
2) I suspect of my having changed ”warning limit'" in setting many times . (you read unskillfully changing )

You run a GPRS app on the phone? (GPRS isn't GPS - they're totally different classes of things.)

Getting back to your question, exactly what is "blocked", internet access (say, getting to this site), or phone calls. Or a specific site or app?

Can't help you without the details, why something happens usually depends on what other things are happening.