You both can try at the end of the url #xnsup maybe it makes it more stable.
It was initially added .
stratum+tcp://stratum-us.granatgas-pool.info:2525#xnsub
I dont understand something ...
In example you can clearly show
stratum+tcp://stratum-us.granatgas-pool.info:2525
/#xnsub
Why do you put this address without
/stratum+tcp://stratum-us.granatgas-pool.info:2525#xnsub
I use this one for my D3 and i assume is working nice
stratum-us.granatgas-pool.info:1111/#xnsub
Since stratum+tcp:// is already default fonction