The Quest Marker above the NPC’s head (!) does not show for some non-trivial quests. It seems to be affecting only green quests that are on the cusp of going trivial (gray). I don’t recall this issue from the past. I did disable all addons to ensure they were not causing an issue.
I’ve noticed this too. Level 41 getting the “A Dwarf and His Tools” quest from Prospector Ryedol in Badlands.
green quests , I’m guessing 1 level from grey do not show the !. Also noticed that.
Workaround, Questie or QuestCodex, enable low level quests in options.