I have Pythia Monte Carlo (MC) samples where I can't understand the parton showering model. If I print out full decay chains from the events, each event contains multiple string objects with pdgId 92. There can be up to 19 strings which are exactly the same and have exactly the same further decay chains, but have different mothers. And this causes a problem that it's impossible to go up in the decay chain from each final state particle and find for example from which quark or gluon the particle is coming. It's possible to identify mothers of each particle up to the string, and then this string has multiple different mothers.
So how does this string-related part work in Pythia?