I have this issue only with Locus. I haven’t seen it with mapsforge apps.
Your Note 2 has scale factor 1.5 (near to 240dpi), so you probably don’t have any problems. But I don't know why. My 240dpi device does also work. The Idea of this testpattern was to make the drawing from outside of the frame visible. Your 64x64 has everything inside the frame.
Here a picture:
Left: What I get.
Right: What I expect.
Locus is drawing the pattern with 26x27 pixel instead of 26x26. It seems the calculation of the height does not work correctly. When I avoid this calculation with declaring the height in the theme, the problem is gone.
This works: <area src="file:/testpattern.svg" symbol-width="26dp" symbol-height="26dp"/>
It is a workaround, but I think it should be corrected in Locus.