Speed Issues with RM520NGLAAR01A08M4G_01.200.01.200 firmware on AT&T

Hello I recently upgraded to RM520NGLAAR01A08M4G_01.200.01.200 on my rm520n-gl however it seems like performance is degraded on AT&T. I reverted back to RM520NGLAAR03A01M4G_A0.200.A0.200 and it seems more stable with speed. Is there another firmware I should use? Can you provide this firmware?

Dear @ikearu
Please use the latest firmware and test again.