I am having this issue too. Unlike some other people having the issue, I only have one character and I am stuck on Nascent Dawn 1/5. I'm doing these quests for the first time because when New Light came out, I never did the Data Recovery quest for some reason, but I started working on Wayfarer late last year and finally got around to grinding Escalation Protocol... and now I cannot do any Mars content at all (um, well, I can, but I get no Resonate Stems from it)! I have only one character and from what I am reading here and on other sites, there is no one who is stuck on 1/5 who was able to create a new character and advance the quest. It's like someone accidentally deleted the node. I've compared screenshots, videos, everything, and there's no node or "song." I have tried dropping the Nascent Dawn quest and then checking for the node -- it isn't there. I did a few rounds of EP and got no Resonate Stems. I picked up the abandoned quest step and tried EP again, no Resonate Stems (this might be the intended outcome because I have the arch key in my inventory it's gated behind the step I can't complete; I don't know). I went back and checked the node -- not there. I restarted the game -- not there. Went back to orbit and loaded back in -- not there. I'm going to try dismantling the key and seeing if redoing the patrols solves this issue because honestly I've spent longer questioning my own eyeballs than I spent doing those patrols and the lost sector.

Having the same issue and I only have one character. I assembled the override frequency when it prompted me to, but it never moved to step 2/5 and that’s where it seems to be hung up (I think). Some people discarded and redid everything over again, but I’ve also seen some people waited over time for it to correct itself... BUNGIE, please fix it!