Hi!
Not sure if I am understanding you entirely correctly but I’d still like to offer you some feedback.
I havent reached level 40 yet (I’m at 32 though), I’ve seen other players in The Grounds at levels past 40.
I do believe you may be talking about the way instant XP and XP-match-packages in consumables cap you at level 25 and 40. However, from there you can still earn XP around The Grounds by playing Drop-ins, Kickabouts, and so forth to earn AXP to pour into your attributes towards the archetype of your player past level 40 😉
hope this helped!