Rattling sceptre skeletal bug

For some reason skeletals raised from Rattling Sceptre keep reserving spirit even for second one of first 2 spawned. I've got sceptre with +32% spirit, my setup is 3 skeletal warriors 2 snipers, on my skill lvl reservation for snipers is 41 spi for each, +33 for extra warr witch give 115 spi reservation. With pool of 132 it give 17 spi left. But for some reason when one sniper die game reserve spirit for 2 warriors instead of just that extra one, and don't revive second sniper untill i manually redistribute spirit points (remove all snipers and all but one warriors and add again) or teleport to the village and all of minions respawn.
On second screenshot you can clearly see that i got 1 sniper and 3 warriors witch shoud give 132-41-33=58 (sniper+extra warr) spi but you can see 25spi left (132-41-33-33 - sniper+2 warriors).
Link for screenshots:
https://photos.google.com/share/AF1QipPNmHXff70S7DwElxLCaCjJ7qwPuuBahQmOe77ssqv_881b_P0jc1GPZPnTQI19-A?key=Sk1tYm1sa3lZVm93TDYzeWFKR2Z6UEJqZUN0dG1n

edit:
It look like it always happening when you got three skeletal warriors and low pool of spirit left. It just happened when i had 3 warriors 1 sniper and Serpent Clan (Spectre gem summon). Serpent Clan died and never respawned again. I had to remove two warriors, then Serpent Clan respawned then i could add both Warriors again. They also respawn if all but one warriors die midfight witch is quite annoying if fight is long and warr don't die frequently because you are one minion less untill one of the those conditions (all but one warriors die / manual spirit redistribution / portal to town) have been met.