Shadow shroom bug

Just reporting a bug, when playing modern day I used shadow shrooms ultimate while it was powered up by the sun producing shadow plant. I used the plant food on it and it worked fine, but when I used another plant food on it, it suddenly just took the poison effect away from every single zombie. After that, there was a gargantuan thay i stunned with the bad breath onion, and once I tried using the shadow shroom on it, it did nothing and just sat there until the gargantuan zombie unfroze and crushed it. Maybe it’s an intentional game design, but atleast the gargantuan zombie being immune to shadow shroom should be fixed. Thx