Witch - Spirit problems

Hi,
I recently started playing as a witch and am experiencing an irritating issue with spirit. While farming, I receive a message stating that my minions are consuming too much spirit and number of them is decreasing. If I change the number of minions (Sceptre skill) to 0 and then back to normal, the issue disappears. Does anyone have a solution to this problem?

15.08 UPDATE
I've seen that bug appears then my minions are spawning from death. I got 3 warrior minions and 4 sniper minions, after their death I've got 3 warriors and 3 snipers, and the most weird thing is that I got only 10 spirit after the bug (with 3/4 minions, I had 12 spirit reservation, after bug 22 spirit with 3/3 minion). One sniper minion at 7 lvl cost 35 spirit, so I lost randomly 25 spirit.