Just bringing this one up again as it happens to me in dungeon runs regularly:
When I cast triplicity, if i cast polymorph too fast it does a polymorph instead of actually detecting I casted the first rune of ressurection just before it…
A similar issue i ran into was if hit after initiating the ritual, it would cancel. Happened frequently when i was farming some melee mobs.
would cast the first rune then it would cancel when i got hit before casting poly