5G dropped To 4G - Throttling ?

[CraigWh_2036388]

For the first few days I received great 5g service, 3 or 4 bars, out of 4. 

3 days and 18gb of usage later, it has been cut to 4G... 3 or 4 bars, out of 4. 

Same device, Same sim, same location. 

I have reset the device, removed and re-inserted the SIM, etc etc

 Still no 5G

 I have checked all my settings, all still enable 5G etc - But only 4G received

Is this a common problem ? 

Am I missing something? 

I hope that smarty don't restrict service based on usage.... 

Please help, I want my 5G back. 

Thank you 

[MSF]

Hello @CraigWh_2036388 . The Smarty web page states that there are no speed caps and unrestricted tethering, so that does seem unlikely.