sorry, i can not find the reason. other child actor component works good. just one class have problem.
maybe i have some useful info:
1, compile that class cost long time.
2, the child actor’s name in world outliner like BP_xxxxx678. this means it was 679th spawned object of this class. i have try to print self->get display name in construction script function. it not invoke on begin play. but invoked hundreds times on compile time.