From my experience the most significant issue DSA faces is that they're incredibly fragmented and disunited. They function more like a loose network of activists who come and go than a political party. Members are allowed more or less to believe and act how they want even if it's unhelpful or harmful to the organization. This manifests in their most prominent members blatantly contradicting the organization's positions, but it also manifests in basic administrative tasks not being completed and a disinterest in building a robust internal culture, camaraderie, and pursuing democraticly decided political goals. They might be able to unite around a (usually local) issue but once that matter is settled or the energy dies down then most people drift away until new wave of activists joins up for something else. It also allows for scattered campaigns as people try to pursue their own interests within the DSA only to not have the organization materially support them because nobody else actually wants to do the thing.

If that's reflective of your experience then I would suggest trying to build a culture of party loyalty, discipline, and focus. Idk how to do that specifically but it probably involves mandatory political education.