Problem occurs when you fakecast Lightning Bolt. It will not reset castsequence and you will have to finish one bolt in order to use Stormstrike again.
Is it a bug? I think castsequence should reset on time no matter if I finished followed spells or not.
Thats because the spell itself has a 20 second cooldown as well. This is whats happening, you press your macro, and it start casting lightning bolt, you interrupt it, then you need to wait 20 seconds for it to reset, regardless how long after you’ve used stormstrike you pressed to start your lightning bolt
With reset=20 you need to wait 20 seconds since the last time that it pressed to reset it if you do not finish your cast. If you do finish your cast, your sequence, is back at stormstrike and you “only” need to wait for its cooldown to be able to use it again.