How macros work is they play them line by line at set intervals of time, and dont add the ability to the queue, so if you don't time it right, say you press your spell just before the gcd has rolled back it, the first line will fail and it will move onto the second.

Related not, you shouldnt be running macros in combat, especially on rdm because it has the least buttons by a fair margin, macros will also lose you casts over the course of a fight due to their clunk/ slowness.