AX 2012 R3 CU12 slowness issue

I have installed AX 2012 R3 CU12 in my Environment like AOS in seperate server and DB in seperate server.

After installation, AX performance became very slow(for navigation itself it takes 30 secs to deliver).

even after i increased both server with 12 cores with 30 GB RAM still im facing slow response.

SQL edition is SQL enterprise 2016.

i am fully followed the instruction which is given in installation guide by Microsoft.

still i am struck up to find the solution.

Is that issue is with SQL 2016 version used?

help me if i am in an wrong approach or any tuning steps need to follow?

Thank in advance.