Can’t heal zombies in PVZ heroes

Every time I used a heal card in Plants vs Zombies Heroes for a zombies, my life stays the same. For instance, I had 3 lives left and used the chopper card that deals -1/-1 plus heal zombie for 1. My life stayed at 3 and the plant  did get the -1/-1. The same happened with the nurse zombie. I tried restarting my device, shutting down the iPad and reloading the game and still have this issue. This issue showed up at latest update.