Encountered the same issue. I can't get slowness to work with /summon. I can tell I have the syntax right, because on the same mob I've got Resistance 5, making it invincible, and that's working fine. But slowness and speed don't seem to have any effect.
Encountered the same issue. I can't get slowness to work with /summon. I can tell I have the syntax right, because on the same mob I've got Resistance 5, making it invincible, and that's working fine. But slowness and speed don't seem to have any effect.