Soul core of Zalatl dont apply on asсendancy stormweawer and other

Soul core of Zalatl give 2% increased mana but due to incorrect calculations
the maximum mana received from them does not give the increased effect of arcane surge with ascendancy stormweawer as shown in the video, although it works for an archmage with the same description.
https://www.youtube.com/watch?v=YmKnJYr446Q&ab_channel=KiriAsh
Thanks for reading