Hello guys.
First of all im from Turkey and I have been on paleo diet for 6 months. I only take fish oil and vitamin D as supplement. I think there is nothing about my diet. Also im on starting strength program for 4 months. I began to do lifts with empty barbell (44 pounds) . Now i can do 198 pounds squat and 220 pounds deadlift 121 pound bench press 77 pounds press and 99 pounds power clean. I got 18.7% bodyfat. I just want to burn my bodyfat and increase my muscle mass. In this 5x system i cant burn fat anymore . Should i begin to lift same numbers for more reps like (10-15 or to fail) to increase muscle mass?

Thanks.

Yeah 4 months is not a long time, but it sounds like you're progressing well.

High volume is good for adding mass via sarcoplasmic hypertrophy (increase in the muscles storage and utilization of fuels/glycogen) but as far as fat burning goes, that's mostly diet.

Take a week off.  If your gains stop you're not eating enough.  Add whole milk if no dairy issues.