internet showing E instead of H+

[salmi]

Im changing my phone to j7 for past few weeks..my internet showing E n i almost cant surf the internet..& sometimes i need to restart the phone, then i'll receive whatsapp msg...but when i change back to my previous phone-lenovo..it does show H+ n super fast,can watch utube without delay...is there any setting that i can set up? @ something wrong with my new phone...thanks in advance!