Timeline reflection quest

[$noochie boochie$]

Playing as a Warlock, this is the last quest I need to complete to increase my rank to level 4 but I can't do it because npc Ikora Ray won't let me get it. Trying to find a solution on my own I came across several comments where people had the same problem. Does anyone have any ideas on how to fix this?
And how critical is it for continuing the game if my rank always remains at level 3?

[Nursemorph]

It's not critical that you go beyond Rank 3...but you won't get things like Armour and Weapon mod unlocks or the extra Loadout slots. This article lists all the Guardian Rank Rewards (scroll down to near the bottom for the complete list of guardian ranks...ignore the requirements etc as they are for an older season):

https://www.blueberries.gg/leveling/guardian-ranks/

Have you checked the lost quest console at the Tower or the HELM? Just in case you accidentally deleted it or something