Thats what I would say it probably is. I know the Sorento has had a few issues of condensation not draining.
Using the below link, please add location and vehicle (year & model) to your signatureI have a 2018 Sorento and the vents have a smell like mildew and vinegar, and it has had this smell all summer, its terrible. I have a baby that also sits in that car! I have had many problems with this car since day one. I am so disappointed that i have completely given up and cannot wait to get rid of this car.