Well I’m finished now, but at the time made this thread - yes am sure was some kinda bug.
I hadn’t done 1st time kills on number of field bosses. Mostly the lower level ones because had leveled so fast I was beyond those tiers and figured I’d go back when I was OP.
So 100% if the challenge icon is supposed to be there until all welcome challenges done, then it bugged out because I had signatus and 2 other lower tier field bosses not done. Went bad recently and got those - my adventure tome showed not killed and now all killed.
Maybe some kinda bug associated with fever time because the icon disappeared just when fever time first launched.