Bug: Necromancer bone golem

Hi I noticed that many times buff from passive golem(second one) increasing thorns %20 is missing/disapear
Sometimes I can retriger it by sacrifice golem and restart setting to use second trait, sometimes I need to remove golem from skill bar and respawn it but after dungeon I have to do this again one or many times to retrigger it buff, I verify it on character statistics which allways show me 20% for warriors(defenders thorn trait) but for golem I sometimes see it sometimes no. Any Ideas or it’s just bug.