Skeletal Brute bug

I'm playing detonate dead build and there is a bug when i try to switch my weapons some of my skeletal brutes do not summon. i summon 4 Skeletal Cleric with my first weapon and 3 Brutes. with my secondary it suppose to summon 7 brutes but it only summons 5 of them. everytime i change my weapons i have to manually change my brute's reserve to fix it. when i do it manually it works. i believe it's about skeletal cleric. because when i change it there should appears exclamation but it doesn't. idk something doesn't work right. Btw. if i change my secondary to 2 clerics 6 brutes it works fine. if i change clerics+brutes to only brutes it doesn't work.And yeah i have enough spirit for it. As i said when i change reserves manually it works.