Hi Bungie, FYI I did risk abandoning the quest and picking it back up, and redid the Survival Agility Challenge and it completed it, I’m now on step 6, so that worked for me.

reposting here for moderator view -- I was stuck at Step 6 - Vex Finishers. I had this on my other 2 characters at different progress and abandoned them with no result. I reluctantly abandoned it on my Hunter. I then went to the kiosk near the postmaster in the tower to reacquire the quest. This returned the quest to my Hunter at the latest quest step (step 6.) I returned to Europa and the quest began proceeding. Hope this helps others. Key thing to note is that you will not lose your quest progress

I just noticed when I logged in about an Exo Weekly Challenge Issue I hope that this isn’t the answer as I did that ie Stasis Kills NOT on Europa that’s the Weekly from the Exo Stranger but the other Weekly Challenge is the one located in Braytech which this week is ‘Agility’ and requires plat forming and shooting enemies to unshield ‘cubes’ to shoot. (Last weeks was stay in the protected areas or ‘biting cold’ kills you unless you killed vex and collected red pyramids to counteract the biting cold. Either way, I did both of those and the weekly ‘stasis kills off Europa’ and didn’t advance the Lament quest. Kills off Europa weekly said just that ‘not on Europa’ so for me there’s no issue with that weekly just maybe some folk misread it and tried kills on Europa. Anyway all we can do is leave it with you to fix later.

Thank you Bungie.