Both portals should the same size. Fitting one in a box, means the box should be too big to fit in the other portal.

To answer your question, yes, we do exist!

Your plant: 🤷

Also, maybe, some weed killer damage…

It needs to get very hot to kill the pathogens. It’s possible, yes, but maybe not in a small bin at home

Never use diseased plants for compost. You only help propagate the disease.