Under extrusion during 3D printing Nylon 4.6?

I have been experiencing under extrusion during 3D printing Nylon 4.6, and I have tried to optimize parameters such as the flow rate, speed, overlap etc. but still not seeing any improvement. I also dried the filament for 3-4 days and still no improvement. Kindly advise.

Which printer model are you using?

I am using Lulzbot TAZ 5