OT – 4015x internet speed problem

Hello, I flashed a custom rom on my Alcatel OT-4015x
The problem is that I had H+ internet speed before flashing. now I have E and it’s too slow… 🙁
And rom is for OT – 4015A which is dual sim maybe there is a problem?.
I want to keep this rom but in the same time I need that HSPA+ speed because of my business.
I know I can port some things from my stock rom into this new one and that will solve the problem, but I don’t know which, can somebody help me? :confused: