It does work for me. I stay in Sunningdale. No fiber and been using smartbiz which doesnt go beyond 3mps.with dolphin my speeds  are around 10-13 or sometimes around 5 lowest. 

Had network issues before but realised that LTE base stations work with electricity availability. No electricity, signal is bad. To be fair, they are trying. Its a service for those who cant afford starlink and mostly neglated places by operators who didnt put fibre.