New! solid shampoo issues

[peridoxical]

I've had a New shampoo puck for a couple years now. (I mostly just use it when I travel, as a special little "F you" you the TSA) I'm using it now and having problems that I've never had before. It's getting all slimy, with this thick hot pink gunk on it. The gunk is so thick that it won't come out of the tin without a knife or something to break the seal. I've tried drying it thoroughly before I put it in the tin, making sure the tin isn't wet and keeping it out of the bathroom in case it was a humidity issue.

Anyone have any ideas why this is happening? I'd rather not throw it away since it still works well on my hair, but I'm concerned the age is a factor.

Thanks in advance!