After playing a Practice Vs. AI game, I levelled up from level 24 to 30 on Baptiste in one go. On the Hero page as well as the Progression page, it now says he is at level 30. However, on the Overview page he’s still listed as level 24.
I didn’t get any of the rewards for levelling up. On the progression page, it now says “Levels to next reward: -5”.
I’ve previously experienced similar progression issues with Lúcio (from level 25 to level 29), Bastion (level 18 to level 22) and Orisa (level 18 to level 21), all of them gaining these levels from XP from a single Practice Vs. AI game each.
Edit: The Overview page now also states that Baptiste is at level 30.