I've messed with this a fair amount & here is my opinion.
The smell will be dictated first by the genetics. You didn't mention the strain. But I can grow 2 different strains in the same cycle, & one will smell almost immediately, & powerfully. The other smells like hay/grass, & any smell won't show up until the cure is finished.
So, assuming your plant is genetically smelly....Co2 used past 5 weeks can cause that hay smell. If your temps were too hot, it can cause it. If you burn them badly it can cause it. This one becomes progressively more dangerous the closer you get to harvest. E.g. I had a plant one time & I didn't time the flush correctly. It still needed to mature but I had flushed everything out. So I gave it some nutes & burned it, I would say a little more than slightly. The plant had previously been smelly, after that, no smell at all, except for that chlorophyl smell during drying. If you are HID with no glass, light proximity can cause it. If you let the plants dry out too much before harvest, I have seen that cause it (as well as a huge hit to resin production).
If you think of all the different definitions of "burn," that covers a lot of the ways you can remove smell.
If the plant is not genetically smelly, there is nothing you can do to change that.
@Seamaiden is correct that a lot of the time, the smell shows up in the jars. If you haven't done any of what I described above, & if the plant has a potent smell genetically, it will show up in the jars.
Curing is under rated in my opinion. That is when things get real. The product becomes smoother on the lungs, the humidity is right, it's nice & sticky. & I would swear the stone is better.
I also agree with the opinion that you haven't had them in the jars long enough. I've had some that want to be in the jars for months.