Decrease drop rate fragment?

During component events in May and before, I always farm and can get dozens even if lucky to get more than 20 low fragments (silver, brown & green) in one full hour.
However, the last 2 component events, 1 hour farming only get 4 low fragments (silver, brown & green).  Even I have tried farming for 5 hours and only got 16 low fragments.
This is very disappointing, because we need low fragments for crafting according to the pattern.

@Fluxxx & @Lexia