My cake was iced with Ganach 3:1 ration, I was able to cover it with fondant and it was one merry moment until I started smoothening it and the cake began to sag -  for some reason  ganache underneath the fondant  was melting or began to fall off the side and gather in the end of the cake- I am now sitting with a sagging cake wondering what to do

I am in hot and humid place but yes I did let the ganached cake sit on the counter for abt 8 hrs to prevent condensation

any help