Metaphlan4 detects Ecoli sp. where Metaphlan3 was not able to detect in same sample

Hi @fbeghini
I ran metaphlan4 on the same data that I had ran on metaphlan3 earlier. I observed that one of the samples was not detecting E.coli in metaphlan3, but now when I used the same sample with metaphlan4 E.coli is getting detected in that sample. I want to know the reason why this would be happening.