Spark don't bounce from walls...

i tested it now in several maps, places and structures.
if i stay right in front of any structure (walls, trees, stones, fences, ...) and face that structure, spark don't bounce, it just stuck in place, it have a like 60-90° radius.
if you dont face the structure it works just fine but if you face it again it beginns to stuck.
it doesn't matter if with or without MTR, its the same.