Found how to fix traits, so apparently recently Paradox made one tag depricated, e.g. 00_trade_unions.txt has:

# Deprecated; use on_enable effect to assign traits instead
traits = { ...

and now, what is needed, is to change on_enable, for all 8 groups with their traits, example:

on_enable = {
ig:ig_trade_unions = {
set_ig_trait = ig_trait:ig_trait_work_to_rule
set_ig_trait = ig_trait:ig_trait_industrial_organizers
set_ig_trait = ig_trait:ig_trait_solidarity
}
}