User blog comment:TheHandsomePlant/Plant Leveling Data/@comment-24735666-20160329213432/@comment-28629433-20160330145353

Just keep bringing him into levels when the new update drops and if you win enough levels with him as one of your chosen plants, he should be back to normal.

Dunno if you have to place him or not to have him level up or not, my guess would be yes you do have to place him.