Thank you! I figured out what positional Y value offset ,
it is in line number 2853 SuperTextMesh.ApplyOffsetDataToTextInfo ()
anchorOffset.y = VerticalLimit> -rawBottomRightTextBounds.y? (-rawBottomRightTextBounds.y rawTopLeftBounds.y - rawBottomRightBounds.y) * 0.5f: 0f;
This happens if only VerticalLimit> -rawBottomRightTextBounds.y respectively.
For my while I just add this offset, you will probably find it easier to figure out where you better need to fix it.