Problem with dropping traps mid fight that I can't put my finger on?

[Cobaltius]

I have noticed for a while when I am mid fight in BG or Ashran for example and I want to drop a frost trap, the trap CDs are up I still can't launch them for what seems to be another 5-10 seconds.

Perhaps I am not seeing the forest for the trees here, is there something else tied to trap CDs so they are not usable when they are off cool down?

[Syncness]

Frost and Ice trap have shared CDs. Perhaps it's that?