When died, minions don't respawn automatically

Hello,
I just reached mapping, I'm doing a witch lich.

I've a Bind Spectre gem with Vaal Guards bombs.

To me already happened several times that, when I die and respawn to the checkpoint, the bind spectre minions won't respawn with me, and I need to manually toggle to 0 and again to 5 for them to reappear.

Other minions like skeletons works normally.

Thanks