3G Streaming cutting in/out

[f0z]

I have spotify on my iphone 6 running IOS 8.

On wifi streaming is fine. On 3G streaming is cutting in/out. I have checked settings and quality is set to normal.

The same issue was happening with my previous iphone 5.

Note: My wife has iphone 5 and she has no issues playing same music in same location over 3G.

Any ideas  ?

I have tried deleting spotify app, clearing safari settings, restarting iphone and reinstalling spotify app.

Thanks for all help/suggestions