If your reactions are strong at immediate spin (3+) and then get weaker at AHG (w+), it could mean the presence of a strong cold antibody.

Cold antibodies tend to be IgM and their optimum phase for reactivity is immediate spin. Incubation and washing of the sample may cause the agglutination that occurred at room temperature to break down. This would appear as a weaker reaction at AHG.

If the reaction strengths varied in each panel cell then that could be an indication that there are multiple antibodies present.

Your screen cells are 3+ at immediate spin and weak (W)+ at AHG. Your auto control is negative for both phases. Some of your antibody panel cells are 3+ at immediate spin and negative at AHG. What should you suspect?