Seimur Oxbone: quests can't be 100% completed on 2nd char

I finished everything on my primary cook last night, then went ahead to repeat the quests on my secondary cook.

Lo and behold, you can't finish up on your second character! I've done all city quests again, cooked three meals per city, delivered the heat stones, went hunting etc, and received every last item/recipe/whatever from the achievement's list (including picking up my oven and cooking ware on that character), yet once done, Seimur still has the quest icon above his head and tells me I am not done and need to see the chef trainers.

I am already Level 500 on that character as well, so I assume this is bugged somehow? Because on my primary cook, upon receiving the final achievement rewards for the first time, the quest icon above Seimur's head was gone for good.

Can someone else confirm this, please?