The serum and blow-drying could have something to do with it. Clarifying couldn't hurt. But... my hair curls *less* when it is short. It is chin length right now and I can get very loose ringlets, but when it is long I can get tighter ones. There's more hair to wind around, so wind it does. It seems counter-intuitive when you think of it as weight, but it makes sense (to me at least) when I think of actual material to curl. It may curl more once the cut settles in.

Since you're happy with how your hair looks early in the day, it sounds like it isn't just the cut. Either something is dragging it down (leftover serum, too much product) or you need more hold because you're getting less of a tight curl to begin with. Hope you find the solution!
I sort of blog
I'm mostly away doing field work through mid-May.

Hair: curlybob, fine, dense, low-po, big waves/ringlets (2C/3A)
Co-Wash: Nature's Gate Herbal Conditioner
RO: YTC Carrot, Aubrey Organics GPB
LI: BS Shea Soft Styling Cream (HG)
Styling: KCCC, Garnier P&C Gel
1xWeek: low-poo, gelatin PT or Joico K-Pak
Hair Likes: aloe, coconut oil, humidity, protein, long walks on the beach