Ninja feels weird

[Jeeqbit]

You are correct that latency causes it to think you only pressed 1 mudra when you pressed 2. Don't worry though; the server is aware that you pressed 2 and should register it as such. It does for me when I play on Materia. Initially it does Fuma Shuriken, then corrects it to Raiton or whatever else I used.

As for latency being an issue just in this game, it is probably a combination of the server's relative distance from you in this game and the fact that Abilities have an animation delay where it waits for the animation to happen first before applying the effect and this is an issue many players don't like but the developers don't see as an issue.