Looking at your stats it seems like a slight drop... dont know about a 3rd. i would also recommend a larger test file. 15 MB is tiny for powerboost standards.
25 MB - https://testmy.net/dl-25MB&nfw=1
50 MB - https://testmy.net/dl-50MB&nfw=1
75 MB - https://testmy.net/dl-75MB&nfw=1
200 MB - https://testmy.net/dl-200MB&nfw=1
Recent Stats.png