Thank you for trying the game!
That feature was intended and was working but broke at some point and I was surprised to find this out from your comment lmao
Probably a blessing in disguise though, as I realize now that it would've been very abuseable in the initial state and would've made the game trivial as the player would be able to get a bunch of HP from one fight to carry them through the whole game.
I will make sure it works in the future updates and also think of a way to make it balanced :D