u/DepartmentOdd7915

Hi all! I picked up my bag this morning after not using it for a few days and random patches on the side/bottom have turned black, sticky, and are very cracked. I don’t remember setting it down in anything and I really don’t know what the black sticky substance could be. Do you know if it’s because of improper care, humidity, or something like that? It’s been very humid where I live for the past couple of days.