I would say it's a bit too early to take a conclusion like that, but you did well coming to the forum and posting your results. If other people come and consistently have the same results as you do, then the possibility of it being underdosed would be more plausible. As for now, there are many circunstancial factors that you may not be considering. Test it again, and compare it to your previous results from other sources, tested under the same circumstances. And , still, it will take a 3 or 4 tests so you can have an average.
But, yeah, continue to test as you would normally do, and if you come across significantly different results from different gear sources, then one of them would have to be underdosed.