Ceystallised power seems to have cap on amount of essences for single bosses?

I have 22 essences guaranteed 100% of the time. I am doing atolls or strands or racecourses or anything where i get every single essence guaranteed. Yet the boss NEVER has 22 essences on them. On ones like strand and racecourse it seems like it allows more (but still never the full expected 22).
Here is a strand the is 0 monsters remaining and it says clearly "22 additional monsters" but only 18 on the final bosses?
Same conditions on mesa get all the essences first 0 monsters except the boss left and kill him and now its WAY less only 14 close to half of the expected 22 (minimum the is additional chance to spawn).

https://www.pathofexile.com/forum/view-thread/3581854/page/1#p25466814
My conclusion from watching someone who uploaded a map clear video where they had this issue is that a boss cannot hold multiple essences of the same type.

That wouldn't explain why you got some 2x drops in the second screenshot, though. I'm not sure how that happened if there was only one boss.

Getting 2 of the same on a single mob is decently commmon. I try to get all the corrupted essences first cause they are worth more so ill chase them around with the adaptation and stability scarab and I have sometimes had 4 of the same essence on one boss and the normal rares 100% can have multiples of the same. So I doute its that I legit think the is just some sort of mob stat text limit being reached.