I’ve submitted several bug reports with screenshot attached since beta about this issue and nothing has been done so far.
In order to this bug to be reproduced properly some patience is needed. The Flesh Golem and The Shadow Fiend pets from the necromancer are the ones that stand idle most during combat but it also happens with the other pets.
When the pets are summoned they assist on the necromancer’s target but after 3 or 4 fights the pets start to stand IDLE while in combat at random intervals.
Please, it is so easy to fix. Give the necromancer the ability to attack the target THE PLAYER WANTS, just like F1 for the Ranger pet attack command and the F3 stop combat return to me