Cerebral Vortex Enemies Trait Stacking?

This might be a small sample bias, but despite the trait saying that the 35% spell gem seal does not stack, I have consistently ran into 2 or even 3 enemy Cerebral Vortexes where I had 65% or even my entire list of spell gems sealed. (I have one person with 5 and one person with 6 spell gems, so I have enough in my party to notice.) I’d double-check if this is the case or not, but I had almost my entire team’s spell gems sealed going against 3 vortexes the other night and either the game really hates my spell gems or something is up.

Steam Windows, v0.1.8

I read another bug report that sealed spells stay for the whole level and not just the battle, if that’s the case that would explain why my spell sealing rates were way higher.