My opponent's turn (I have Red Dragon Arch, Plaguesreader and Crystron Needlef: going for Formula Synchron with NeedleFiber). On chain to my opponent Spell/Monster Effect Activation, I synchro summon with Formula effect for Calamity..... and Calamity s effect doesnt activate
It doesnt work on chain cause it miss timing or is it a bug?

Calamity text

When this card is Synchro Summoned: You can

It is missing the timing
http://yugioh.wikia.com/wiki/Missing_the_Timing 

Like i thought, asked for knowing for sure