Hello. I have a plant that was given to me about 6 years ago and was told it is a peace plant or spath. ??? I dont know what the proper name of it, sorry. It has grown very large and looks so nice but I have just noticed a sour milk smell in it this morning. There is no children in my house to put anything in it and I have not done anything out of the ordinary with it, just water and sometimes fertilizer. It is not soaking wet. I let it get almost dry then water again and do not let it set in a puddle. I dont want to lose this plant so thought I would ask the experts here. Thank you.